diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..1020f5d
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,35 @@
+version: 2
+updates:
+  # Enable version updates for Gradle dependencies
+  - package-ecosystem: "gradle"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "monday"
+      time: "09:00"
+    open-pull-requests-limit: 10
+    reviewers:
+      - "KidsPOSProject/android-team"
+    labels:
+      - "dependencies"
+      - "android"
+    commit-message:
+      prefix: "chore"
+      include: "scope"
+    
+  # Enable version updates for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "monday"
+      time: "09:00"
+    open-pull-requests-limit: 5
+    reviewers:
+      - "KidsPOSProject/devops"
+    labels:
+      - "github-actions"
+      - "ci/cd"
+    commit-message:
+      prefix: "ci"
+      include: "scope"
\ No newline at end of file
diff --git a/.github/workflows/android-ci.yml b/.github/workflows/android-ci.yml
new file mode 100644
index 0000000..646d1d0
--- /dev/null
+++ b/.github/workflows/android-ci.yml
@@ -0,0 +1,176 @@
+name: Android CI
+
+on:
+  push:
+    branches: [ main, develop, feat-* ]
+  pull_request:
+    branches: [ main, develop ]
+
+jobs:
+  lint:
+    name: Lint Check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        
+      - name: Setup JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+          
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+        
+      - name: Run Lint
+        run: ./gradlew lintProdDebug lintDemoDebug
+
+      - name: Upload Lint Results
+        if: always()
+        uses: actions/upload-artifact@v3
+        with:
+          name: lint-results
+          path: app/build/reports/lint-results-*.html
+
+  unit-tests:
+    name: Unit Tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        
+      - name: Setup JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+          
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+        
+      - name: Run Unit Tests
+        run: ./gradlew testProdDebugUnitTest testDemoDebugUnitTest
+        
+      - name: Generate Test Report
+        if: always()
+        run: ./gradlew jacocoTestReport
+        
+      - name: Upload Unit Test Results
+        if: always()
+        uses: actions/upload-artifact@v3
+        with:
+          name: unit-test-results
+          path: app/build/reports/tests/testProdDebugUnitTest/
+          
+      - name: Upload Code Coverage
+        if: always()
+        uses: actions/upload-artifact@v3
+        with:
+          name: code-coverage
+          path: app/build/reports/jacoco/jacocoTestReport/
+
+      - name: Upload coverage to Codecov
+        if: always()
+        uses: codecov/codecov-action@v3
+        with:
+          file: app/build/reports/jacoco/jacocoTestReport/jacocoTestReport.xml
+          flags: unit-tests
+          name: unit-tests-coverage
+
+  instrumented-tests:
+    name: Instrumented Tests
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        api-level: [26, 29, 33]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        
+      - name: Setup JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+          
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+        
+      - name: Cache AVD
+        uses: actions/cache@v3
+        id: avd-cache
+        with:
+          path: |
+            ~/.android/avd/*
+            ~/.android/adb*
+          key: avd-${{ matrix.api-level }}
+          
+      - name: Create AVD and generate snapshot for caching
+        if: steps.avd-cache.outputs.cache-hit != 'true'
+        uses: reactivecircus/android-emulator-runner@v2
+        with:
+          api-level: ${{ matrix.api-level }}
+          force-avd-creation: false
+          emulator-options: -no-window -gpu swiftshader_indirect -noaudio -no-boot-anim -camera-back none
+          disable-animations: false
+          script: echo "Generated AVD snapshot for caching."
+          
+      - name: Run Instrumented Tests
+        uses: reactivecircus/android-emulator-runner@v2
+        with:
+          api-level: ${{ matrix.api-level }}
+          force-avd-creation: false
+          emulator-options: -no-snapshot-save -no-window -gpu swiftshader_indirect -noaudio -no-boot-anim -camera-back none
+          disable-animations: true
+          script: ./gradlew connectedProdDebugAndroidTest
+          
+      - name: Upload Instrumented Test Results
+        if: always()
+        uses: actions/upload-artifact@v3
+        with:
+          name: instrumented-test-results-${{ matrix.api-level }}
+          path: app/build/reports/androidTests/connected/
+
+  build:
+    name: Build APK
+    runs-on: ubuntu-latest
+    needs: [lint, unit-tests]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        
+      - name: Setup JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+          
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+        
+      - name: Build Debug APK
+        run: ./gradlew assembleProdDebug assembleDemoDebug
+        
+      - name: Upload APK
+        uses: actions/upload-artifact@v3
+        with:
+          name: debug-apk
+          path: |
+            app/build/outputs/apk/prod/debug/*.apk
+            app/build/outputs/apk/demo/debug/*.apk
+            
+      - name: Build Release APK
+        run: ./gradlew assembleProdRelease assembleDemoRelease
+        
+      - name: Upload Release APK
+        uses: actions/upload-artifact@v3
+        with:
+          name: release-apk
+          path: |
+            app/build/outputs/apk/prod/release/*.apk
+            app/build/outputs/apk/demo/release/*.apk
\ No newline at end of file
diff --git a/.github/workflows/pr-checks.yml b/.github/workflows/pr-checks.yml
new file mode 100644
index 0000000..0b93bc0
--- /dev/null
+++ b/.github/workflows/pr-checks.yml
@@ -0,0 +1,120 @@
+name: PR Checks
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  danger-check:
+    name: Danger Check
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.head.repo.full_name == github.repository
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.0'
+          bundler-cache: true
+          
+      - name: Install Danger
+        run: |
+          gem install danger
+          gem install danger-android_lint
+          
+      - name: Run Danger
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: danger
+
+  code-quality:
+    name: Code Quality Checks
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          
+      - name: Setup JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+          
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+        
+      - name: Run Detekt
+        run: ./gradlew detekt
+        
+      - name: Upload Detekt Results
+        if: always()
+        uses: actions/upload-artifact@v3
+        with:
+          name: detekt-results
+          path: app/build/reports/detekt/
+          
+      - name: Check Kotlin Code Style
+        run: ./gradlew ktlintCheck
+        
+      - name: Comment PR
+        if: always()
+        uses: actions/github-script@v6
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const fs = require('fs');
+            const path = require('path');
+            
+            // Read lint results if available
+            let comment = '## Code Quality Report\n\n';
+            
+            try {
+              // Add results summary
+              comment += '### Summary\n';
+              comment += '- [x] Code style checks completed\n';
+              comment += '- [x] Static analysis completed\n';
+              
+              // Post comment
+              github.rest.issues.createComment({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                body: comment
+              });
+            } catch (error) {
+              console.log('Error posting comment:', error);
+            }
+
+  size-check:
+    name: APK Size Check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        
+      - name: Setup JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+          
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+        
+      - name: Build APK
+        run: ./gradlew assembleProdRelease
+        
+      - name: Check APK Size
+        run: |
+          APK_SIZE=$(ls -la app/build/outputs/apk/prod/release/*.apk | awk '{print $5}')
+          APK_SIZE_MB=$(echo "scale=2; $APK_SIZE / 1048576" | bc)
+          echo "APK Size: ${APK_SIZE_MB} MB"
+          
+          # Fail if APK is larger than 50MB
+          if (( $(echo "$APK_SIZE_MB > 50" | bc -l) )); then
+            echo "Error: APK size exceeds 50MB limit"
+            exit 1
+          fi
\ No newline at end of file
diff --git a/Dangerfile b/Dangerfile
new file mode 100644
index 0000000..b964b1f
--- /dev/null
+++ b/Dangerfile
@@ -0,0 +1,26 @@
+# Check PR size
+warn("Big PR! Consider breaking it up into smaller ones.") if git.lines_of_code > 500
+
+# Warn when there's no PR description
+warn("Please provide a PR description") if github.pr_body.length < 10
+
+# Check for modified test files
+has_test_changes = git.modified_files.any? { |file| file.include?("Test.kt") }
+has_source_changes = git.modified_files.any? { |file| file.include?("src/main") }
+
+if has_source_changes && !has_test_changes
+  warn("You modified source files but didn't add or modify any tests. Please consider adding tests.")
+end
+
+# Check for TODO/FIXME comments
+for file in git.modified_files
+  next unless file.end_with?(".kt", ".java")
+  
+  diff = git.diff_for_file(file)
+  if diff && diff.patch.include?("TODO") || diff.patch.include?("FIXME")
+    warn("TODO/FIXME comment added in #{file}")
+  end
+end
+
+# Congratulate on adding tests
+message("Great job adding tests! 🎉") if has_test_changes
\ No newline at end of file
diff --git a/app/build.gradle b/app/build.gradle
index f13e4c8..ca900ad 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -13,6 +13,8 @@ plugins {
     id 'com.google.dagger.hilt.android'
 }
 
+apply from: 'jacoco.gradle'
+
 android {
     namespace 'info.nukoneko.cuc.android.kidspos'
 
@@ -30,8 +32,9 @@ android {
     }
 
     buildFeatures {
-        dataBinding true
+        dataBinding false
         viewBinding true
+        buildConfig true
     }
 
     // ストアに出さないのでそのまま開発用
@@ -101,7 +104,6 @@ dependencies {
     implementation libs.kotlin.std.lib
     implementation libs.kotlinx.coroutines.android
     implementation libs.dagger.hilt.android
-    implementation libs.kotlinx.serialization
     implementation libs.kotlinx.serialization.json
     kapt libs.dagger.hilt.android.compiler
 
@@ -136,4 +138,26 @@ dependencies {
 
     implementation libs.logger
     implementation libs.eventbus
+    
+    // Unit Testing
+    testImplementation libs.test.junit
+    testImplementation libs.test.androidx.test.core.ktx
+    testImplementation libs.test.androidx.core.testing
+    testImplementation libs.test.hamcrest
+    testImplementation libs.test.kotlinx.coroutines.test
+    testImplementation libs.test.mockito.inline
+    testImplementation libs.test.mockito.kotlin
+    testImplementation libs.test.okhttp.mockwebserver
+    testImplementation libs.test.robolectric.client
+    
+    // Instrumented Testing
+    androidTestImplementation libs.test.androidx.test.core.ktx
+    androidTestImplementation libs.test.androidx.test.runner
+    androidTestImplementation libs.test.androidx.test.rules
+    androidTestImplementation libs.test.androidx.test.junit.ktx
+    androidTestImplementation libs.test.espresso.core
+    androidTestImplementation libs.test.espresso.contrib
+    androidTestImplementation libs.test.espresso.intents
+    androidTestImplementation libs.test.mockito.android
+    debugImplementation libs.test.androidx.core.testing
 }
diff --git a/app/jacoco.gradle b/app/jacoco.gradle
new file mode 100644
index 0000000..20f9d99
--- /dev/null
+++ b/app/jacoco.gradle
@@ -0,0 +1,91 @@
+apply plugin: 'jacoco'
+
+jacoco {
+    toolVersion = "0.8.11"
+}
+
+android {
+    buildTypes {
+        debug {
+            testCoverageEnabled true
+        }
+    }
+}
+
+tasks.withType(Test) {
+    jacoco.includeNoLocationClasses = true
+    jacoco.excludes = ['jdk.internal.*']
+}
+
+task jacocoTestReport(type: JacocoReport, dependsOn: ['testDebugUnitTest', 'createDebugCoverageReport']) {
+    reports {
+        xml.required = true
+        html.required = true
+    }
+
+    def fileFilter = [
+            '**/R.class',
+            '**/R$*.class',
+            '**/BuildConfig.*',
+            '**/Manifest*.*',
+            '**/*Test*.*',
+            'android/**/*.*',
+            // Exclude Dagger/Hilt generated files
+            '**/*_Factory.class',
+            '**/*_MembersInjector.class',
+            '**/*_HiltModules.class',
+            '**/*Hilt*.class',
+            '**/*_Impl*.class',
+            // Exclude View Binding
+            '**/*Binding*.class',
+            // Exclude generated serializers
+            '**/*$serializer.class',
+            '**/*$Companion.class'
+    ]
+
+    def debugTree = fileTree(dir: "${buildDir}/intermediates/javac/prodDebug/classes", excludes: fileFilter)
+    def kotlinDebugTree = fileTree(dir: "${buildDir}/tmp/kotlin-classes/prodDebug", excludes: fileFilter)
+    def mainSrc = "${project.projectDir}/src/main/kotlin"
+
+    sourceDirectories.setFrom(files([mainSrc]))
+    classDirectories.setFrom(files([debugTree, kotlinDebugTree]))
+    executionData.setFrom(fileTree(dir: "$buildDir", includes: [
+            "outputs/unit_test_code_coverage/prodDebugUnitTest/testProdDebugUnitTest.exec",
+            "outputs/code_coverage/prodDebugAndroidTest/connected/coverage.ec"
+    ]))
+}
+
+task jacocoTestCoverageVerification(type: JacocoCoverageVerification, dependsOn: ['jacocoTestReport']) {
+    sourceDirectories.setFrom(files([android.sourceSets.main.java.srcDirs]))
+    classDirectories.setFrom(files([
+            fileTree(dir: "${buildDir}/intermediates/javac/prodDebug/classes"),
+            fileTree(dir: "${buildDir}/tmp/kotlin-classes/prodDebug")
+    ]))
+    executionData.setFrom(files("${buildDir}/jacoco/testProdDebugUnitTest.exec"))
+
+    violationRules {
+        rule {
+            limit {
+                minimum = 0.70 // 70% code coverage
+            }
+        }
+
+        rule {
+            element = 'CLASS'
+            excludes = [
+                    'info.nukoneko.cuc.android.kidspos.di.*',
+                    'info.nukoneko.cuc.android.kidspos.entity.*',
+                    'info.nukoneko.cuc.android.kidspos.event.*',
+                    '*.R',
+                    '*.R$*',
+                    '*.BuildConfig',
+                    '*.Manifest*',
+                    '*_ViewBinding*'
+            ]
+            limit {
+                counter = 'LINE'
+                minimum = 0.60
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/testutil/EspressoTestUtil.kt b/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/testutil/EspressoTestUtil.kt
new file mode 100644
index 0000000..58c02b0
--- /dev/null
+++ b/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/testutil/EspressoTestUtil.kt
@@ -0,0 +1,58 @@
+package info.nukoneko.cuc.android.kidspos.testutil
+
+import android.view.View
+import androidx.test.espresso.UiController
+import androidx.test.espresso.ViewAction
+import androidx.test.espresso.matcher.ViewMatchers.isRoot
+import org.hamcrest.Matcher
+
+/**
+ * Utility functions for Espresso UI tests
+ */
+object EspressoTestUtil {
+    
+    /**
+     * Wait for a specified amount of time
+     */
+    fun waitFor(millis: Long): ViewAction {
+        return object : ViewAction {
+            override fun getConstraints(): Matcher<View> = isRoot()
+            
+            override fun getDescription(): String = "Wait for $millis milliseconds"
+            
+            override fun perform(uiController: UiController, view: View) {
+                uiController.loopMainThreadForAtLeast(millis)
+            }
+        }
+    }
+    
+    /**
+     * Click on a view without checking if it's displayed
+     */
+    fun forceClick(): ViewAction {
+        return object : ViewAction {
+            override fun getConstraints(): Matcher<View> = isRoot()
+            
+            override fun getDescription(): String = "Force click"
+            
+            override fun perform(uiController: UiController, view: View) {
+                view.performClick()
+            }
+        }
+    }
+    
+    /**
+     * Check if a view exists in the hierarchy (may not be visible)
+     */
+    fun exists(): ViewAction {
+        return object : ViewAction {
+            override fun getConstraints(): Matcher<View> = isRoot()
+            
+            override fun getDescription(): String = "Check if view exists"
+            
+            override fun perform(uiController: UiController, view: View) {
+                // No-op, just checking existence
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/launch/LaunchActivityTest.kt b/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/launch/LaunchActivityTest.kt
new file mode 100644
index 0000000..8c639c9
--- /dev/null
+++ b/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/launch/LaunchActivityTest.kt
@@ -0,0 +1,80 @@
+package info.nukoneko.cuc.android.kidspos.ui.launch
+
+import androidx.test.core.app.ActivityScenario
+import androidx.test.espresso.Espresso.onView
+import androidx.test.espresso.action.ViewActions.click
+import androidx.test.espresso.assertion.ViewAssertions.matches
+import androidx.test.espresso.intent.Intents
+import androidx.test.espresso.intent.matcher.IntentMatchers
+import androidx.test.espresso.matcher.ViewMatchers.*
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.LargeTest
+import info.nukoneko.cuc.android.kidspos.R
+import info.nukoneko.cuc.android.kidspos.ui.main.MainActivity
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+@LargeTest
+class LaunchActivityTest {
+    
+    @Before
+    fun setUp() {
+        Intents.init()
+    }
+    
+    @After
+    fun tearDown() {
+        Intents.release()
+    }
+    
+    @Test
+    fun testLaunchActivityDisplaysCorrectly() {
+        // Launch the activity
+        ActivityScenario.launch(LaunchActivity::class.java)
+        
+        // Verify the launcher image is displayed
+        onView(withId(R.id.launcher_image))
+            .check(matches(isDisplayed()))
+        
+        // Verify practice mode button is displayed
+        onView(withId(R.id.practice_button))
+            .check(matches(isDisplayed()))
+            .check(matches(withText("れんしゅう")))
+            .check(matches(isEnabled()))
+        
+        // Verify register mode button is displayed
+        onView(withId(R.id.register_button))
+            .check(matches(isDisplayed()))
+            .check(matches(withText("ほんばん")))
+            .check(matches(isEnabled()))
+    }
+    
+    @Test
+    fun testPracticeModeButtonLaunchesMainActivity() {
+        // Launch the activity
+        ActivityScenario.launch(LaunchActivity::class.java)
+        
+        // Click practice mode button
+        onView(withId(R.id.practice_button))
+            .perform(click())
+        
+        // Verify MainActivity intent is launched
+        Intents.intended(IntentMatchers.hasComponent(MainActivity::class.java.name))
+    }
+    
+    @Test
+    fun testRegisterModeButtonLaunchesMainActivity() {
+        // Launch the activity
+        ActivityScenario.launch(LaunchActivity::class.java)
+        
+        // Click register mode button
+        onView(withId(R.id.register_button))
+            .perform(click())
+        
+        // Verify MainActivity intent is launched
+        Intents.intended(IntentMatchers.hasComponent(MainActivity::class.java.name))
+    }
+}
\ No newline at end of file
diff --git a/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/main/MainActivityTest.kt b/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/main/MainActivityTest.kt
new file mode 100644
index 0000000..84cc22c
--- /dev/null
+++ b/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/main/MainActivityTest.kt
@@ -0,0 +1,92 @@
+package info.nukoneko.cuc.android.kidspos.ui.main
+
+import androidx.test.core.app.ActivityScenario
+import androidx.test.espresso.Espresso.onView
+import androidx.test.espresso.action.ViewActions.click
+import androidx.test.espresso.assertion.ViewAssertions.matches
+import androidx.test.espresso.matcher.ViewMatchers.*
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.LargeTest
+import info.nukoneko.cuc.android.kidspos.R
+import org.hamcrest.Matchers.allOf
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+@LargeTest
+class MainActivityTest {
+    
+    @Test
+    fun testMainActivityLaunches() {
+        // Launch the activity
+        ActivityScenario.launch(MainActivity::class.java)
+        
+        // Verify toolbar is displayed
+        onView(withId(R.id.toolbar))
+            .check(matches(isDisplayed()))
+        
+        // Verify navigation drawer button is displayed
+        onView(withContentDescription(R.string.navigation_drawer_open))
+            .check(matches(isDisplayed()))
+    }
+    
+    @Test
+    fun testNavigationDrawerOpensAndCloses() {
+        // Launch the activity
+        ActivityScenario.launch(MainActivity::class.java)
+        
+        // Open navigation drawer
+        onView(withContentDescription(R.string.navigation_drawer_open))
+            .perform(click())
+        
+        // Verify drawer header is displayed
+        onView(withId(R.id.drawer_header))
+            .check(matches(isDisplayed()))
+        
+        // Close drawer by clicking outside
+        onView(withId(R.id.drawer_layout))
+            .perform(click())
+    }
+    
+    @Test
+    fun testToolbarMenuItemsAreAccessible() {
+        // Launch the activity
+        ActivityScenario.launch(MainActivity::class.java)
+        
+        // Verify settings action is available
+        onView(withId(R.id.action_setting))
+            .check(matches(isDisplayed()))
+            .check(matches(isClickable()))
+        
+        // Verify store selection action is available
+        onView(withId(R.id.action_store))
+            .check(matches(isDisplayed()))
+            .check(matches(isClickable()))
+    }
+    
+    @Test
+    fun testFragmentContainerIsDisplayed() {
+        // Launch the activity
+        ActivityScenario.launch(MainActivity::class.java)
+        
+        // Verify fragment container is present
+        onView(withId(R.id.content))
+            .check(matches(isDisplayed()))
+    }
+    
+    @Test
+    fun testBottomButtonsAreDisplayed() {
+        // Launch the activity
+        ActivityScenario.launch(MainActivity::class.java)
+        
+        // Verify clear button is displayed
+        onView(allOf(withId(R.id.clear_button), withText("とりけし")))
+            .check(matches(isDisplayed()))
+            .check(matches(isEnabled()))
+        
+        // Verify account button is displayed but initially disabled
+        onView(allOf(withId(R.id.account_button), withText("おかいけい")))
+            .check(matches(isDisplayed()))
+            .check(matches(isNotEnabled()))
+    }
+}
\ No newline at end of file
diff --git a/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListFragmentTest.kt b/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListFragmentTest.kt
new file mode 100644
index 0000000..64091fe
--- /dev/null
+++ b/app/src/androidTest/java/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListFragmentTest.kt
@@ -0,0 +1,84 @@
+package info.nukoneko.cuc.android.kidspos.ui.main.itemlist
+
+import androidx.fragment.app.testing.launchFragmentInContainer
+import androidx.test.espresso.Espresso.onView
+import androidx.test.espresso.assertion.ViewAssertions.matches
+import androidx.test.espresso.matcher.ViewMatchers.*
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.MediumTest
+import info.nukoneko.cuc.android.kidspos.R
+import org.hamcrest.Matchers.allOf
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+@MediumTest
+class ItemListFragmentTest {
+    
+    @Test
+    fun testFragmentDisplaysInitialState() {
+        // Launch fragment
+        launchFragmentInContainer<ItemListFragment>()
+        
+        // Verify price view shows initial value
+        onView(withId(R.id.price_view))
+            .check(matches(isDisplayed()))
+            .check(matches(withText("0 リバー")))
+        
+        // Verify recycler view is displayed
+        onView(withId(R.id.recycler_view))
+            .check(matches(isDisplayed()))
+        
+        // Verify no items message is displayed when list is empty
+        onView(withId(R.id.no_item_message))
+            .check(matches(isDisplayed()))
+    }
+    
+    @Test
+    fun testStaffVisibilityWhenNotLoggedIn() {
+        // Launch fragment
+        launchFragmentInContainer<ItemListFragment>()
+        
+        // Verify staff label is not visible
+        onView(withId(R.id.current_staff_label))
+            .check(matches(withEffectiveVisibility(Visibility.INVISIBLE)))
+        
+        // Verify staff text is not visible
+        onView(withId(R.id.current_staff_text))
+            .check(matches(withEffectiveVisibility(Visibility.INVISIBLE)))
+    }
+    
+    @Test
+    fun testBarcodeInputIsEnabled() {
+        // Launch fragment
+        launchFragmentInContainer<ItemListFragment>()
+        
+        // Verify barcode input field is displayed and enabled
+        onView(withId(R.id.barcode_input))
+            .check(matches(isDisplayed()))
+            .check(matches(isEnabled()))
+            .check(matches(withHint("バーコード")))
+    }
+    
+    @Test
+    fun testClearButtonFunctionality() {
+        // Launch fragment
+        launchFragmentInContainer<ItemListFragment>()
+        
+        // Verify clear button is displayed and enabled
+        onView(allOf(withId(R.id.clear_button), withText("とりけし")))
+            .check(matches(isDisplayed()))
+            .check(matches(isEnabled()))
+    }
+    
+    @Test
+    fun testAccountButtonInitiallyDisabled() {
+        // Launch fragment
+        launchFragmentInContainer<ItemListFragment>()
+        
+        // Verify account button is displayed but disabled
+        onView(allOf(withId(R.id.account_button), withText("おかいけい")))
+            .check(matches(isDisplayed()))
+            .check(matches(isNotEnabled()))
+    }
+}
\ No newline at end of file
diff --git a/app/src/debug/res/values/strings.xml b/app/src/debug/res/values/strings.xml
index cfc36e6..816a340 100644
--- a/app/src/debug/res/values/strings.xml
+++ b/app/src/debug/res/values/strings.xml
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string name="app_name">KidsPOS(Debug)</string>
-</resources>
\ No newline at end of file
+</resources>
diff --git a/app/src/demo/kotlin/info/nukoneko/cuc/android/kidspos/ProjectSettings.kt b/app/src/demo/kotlin/info/nukoneko/cuc/android/kidspos/ProjectSettings.kt
index 4e83dbc..0be098d 100644
--- a/app/src/demo/kotlin/info/nukoneko/cuc/android/kidspos/ProjectSettings.kt
+++ b/app/src/demo/kotlin/info/nukoneko/cuc/android/kidspos/ProjectSettings.kt
@@ -2,4 +2,4 @@ package info.nukoneko.cuc.android.kidspos
 
 object ProjectSettings {
     const val DEMO_MODE = true
-}
\ No newline at end of file
+}
diff --git a/app/src/demo/res/values/strings.xml b/app/src/demo/res/values/strings.xml
index 643c73e..4b546a1 100644
--- a/app/src/demo/res/values/strings.xml
+++ b/app/src/demo/res/values/strings.xml
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string name="app_name">KidsPOS(Demo)</string>
-</resources>
\ No newline at end of file
+</resources>
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/EventBusImpl.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/EventBusImpl.kt
index 06dc23e..56d4acd 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/EventBusImpl.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/EventBusImpl.kt
@@ -16,4 +16,4 @@ class EventBusImpl : EventBus {
     override fun post(event: Event) {
         bus.post(event)
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/ServerSelectionInterceptor.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/ServerSelectionInterceptor.kt
index 47a0aaa..62fa293 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/ServerSelectionInterceptor.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/ServerSelectionInterceptor.kt
@@ -12,4 +12,4 @@ class ServerSelectionInterceptor(var serverAddress: String) : Interceptor {
         }
         return chain.proceed(request)
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/extensions/FragmentExtensions.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/extensions/FragmentExtensions.kt
index 1c5a3e9..6d36501 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/extensions/FragmentExtensions.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/extensions/FragmentExtensions.kt
@@ -3,5 +3,12 @@ package info.nukoneko.cuc.android.kidspos.extensions
 import androidx.fragment.app.Fragment
 
 inline fun <reified T> Fragment.lazyWithArgs(key: String): Lazy<T> {
-    return lazy { arguments!!.get(key) as T }
+    return lazy {
+        when (T::class) {
+            String::class -> arguments!!.getString(key) as T
+            Int::class -> arguments!!.getInt(key) as T
+            Boolean::class -> arguments!!.getBoolean(key) as T
+            else -> arguments!!.getSerializable(key) as T
+        }
+    }
 }
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/common/ErrorDialogFragment.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/common/ErrorDialogFragment.kt
index 50b024c..84ffbd9 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/common/ErrorDialogFragment.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/common/ErrorDialogFragment.kt
@@ -1,4 +1,3 @@
-@file:Suppress("EXPERIMENTAL_API_USAGE")
 
 package info.nukoneko.cuc.android.kidspos.ui.common
 
@@ -11,7 +10,8 @@ import info.nukoneko.cuc.android.kidspos.R
 import info.nukoneko.cuc.android.kidspos.extensions.lazyWithArgs
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.channels.BroadcastChannel
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import kotlin.coroutines.CoroutineContext
 
@@ -24,7 +24,7 @@ class ErrorDialogFragment : DialogFragment(), CoroutineScope {
         OK
     }
 
-    private val channel = BroadcastChannel<DialogResult>(1)
+    private val resultFlow = MutableSharedFlow<DialogResult>(replay = 1)
 
     override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
         return AlertDialog.Builder(requireContext())
@@ -32,7 +32,7 @@ class ErrorDialogFragment : DialogFragment(), CoroutineScope {
             .setMessage(message)
             .setPositiveButton(android.R.string.ok) { _, _ ->
                 launch {
-                    channel.send(DialogResult.OK)
+                    resultFlow.emit(DialogResult.OK)
                 }
             }
             .setCancelable(false)
@@ -55,7 +55,7 @@ class ErrorDialogFragment : DialogFragment(), CoroutineScope {
                 }
             }
             fragment.show(fragmentManager, message)
-            return fragment.channel.openSubscription().receive()
+            return fragment.resultFlow.first()
         }
 
     }
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/launch/LaunchActivity.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/launch/LaunchActivity.kt
index 87a92e0..10433e9 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/launch/LaunchActivity.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/launch/LaunchActivity.kt
@@ -2,13 +2,14 @@ package info.nukoneko.cuc.android.kidspos.ui.launch
 
 import android.os.Bundle
 import android.os.Handler
+import android.os.Looper
 import androidx.appcompat.app.AppCompatActivity
 
 import info.nukoneko.cuc.android.kidspos.R
 import info.nukoneko.cuc.android.kidspos.ui.main.MainActivity
 
 class LaunchActivity : AppCompatActivity() {
-    private val handler = Handler()
+    private val handler = Handler(Looper.getMainLooper())
     private val task = Runnable {
         if (isFinishing) return@Runnable
         MainActivity.createIntentWithClearTask(this@LaunchActivity)
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainActivity.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainActivity.kt
index 30180f3..57e97d6 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainActivity.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainActivity.kt
@@ -6,7 +6,6 @@ import android.os.Bundle
 import android.widget.Toast
 import androidx.appcompat.app.ActionBarDrawerToggle
 import androidx.core.view.GravityCompat
-import androidx.databinding.DataBindingUtil
 import com.google.android.material.navigation.NavigationView
 import info.nukoneko.cuc.android.kidspos.ProjectSettings
 import info.nukoneko.cuc.android.kidspos.R
@@ -60,7 +59,8 @@ class MainActivity : BaseBarcodeReadableActivity(), CoroutineScope {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
+        binding = ActivityMainBinding.inflate(layoutInflater)
+        setContentView(binding.root)
         setSupportActionBar(binding.toolbar)
         val toggle = ActionBarDrawerToggle(
             this, binding.drawerLayout, binding.toolbar,
@@ -69,10 +69,7 @@ class MainActivity : BaseBarcodeReadableActivity(), CoroutineScope {
         binding.drawerLayout.addDrawerListener(toggle)
         toggle.syncState()
         binding.navView.setNavigationItemSelectedListener(navigationListener)
-        binding.viewModel = myViewModel.also {
-            it.listener = listener
-        }
-        binding.lifecycleOwner = this
+        myViewModel.listener = listener
         supportFragmentManager.beginTransaction()
             .replace(R.id.fragment_container, ItemListFragment.newInstance(), "itemList")
             .commit()
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/calculate/AccountResultDialogFragment.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/calculate/AccountResultDialogFragment.kt
index 6968487..f6a3cdb 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/calculate/AccountResultDialogFragment.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/calculate/AccountResultDialogFragment.kt
@@ -1,4 +1,3 @@
-@file:Suppress("EXPERIMENTAL_API_USAGE")
 
 package info.nukoneko.cuc.android.kidspos.ui.main.calculate
 
@@ -15,7 +14,8 @@ import info.nukoneko.cuc.android.kidspos.databinding.FragmentAccountResultDialog
 import info.nukoneko.cuc.android.kidspos.extensions.lazyWithArgs
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.channels.BroadcastChannel
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import kotlin.coroutines.CoroutineContext
 
@@ -28,7 +28,7 @@ class AccountResultDialogFragment : DialogFragment(), CoroutineScope {
         Cancel
     }
 
-    private val channel = BroadcastChannel<DialogResult>(1)
+    private val resultFlow = MutableSharedFlow<DialogResult>(replay = 1)
 
     private lateinit var binding: FragmentAccountResultDialogBinding
 
@@ -57,13 +57,13 @@ class AccountResultDialogFragment : DialogFragment(), CoroutineScope {
         }
         binding.result4.findViewById<View>(R.id.ok).setOnClickListener {
             launch {
-                channel.send(DialogResult.OK)
+                resultFlow.emit(DialogResult.OK)
                 dialog?.dismiss()
             }
         }
         binding.result4.findViewById<View>(R.id.go_back).setOnClickListener {
             launch {
-                channel.send(DialogResult.Cancel)
+                resultFlow.emit(DialogResult.Cancel)
                 dialog?.dismiss()
             }
         }
@@ -75,7 +75,7 @@ class AccountResultDialogFragment : DialogFragment(), CoroutineScope {
 
     suspend fun showAndSuspend(fm: FragmentManager, tag: String? = null): DialogResult {
         show(fm, tag)
-        return channel.openSubscription().receive()
+        return resultFlow.first()
     }
 
     companion object {
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/calculate/CalculatorDialogFragment.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/calculate/CalculatorDialogFragment.kt
index c1e24cf..ed3024b 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/calculate/CalculatorDialogFragment.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/calculate/CalculatorDialogFragment.kt
@@ -6,7 +6,6 @@ import android.view.View
 import android.view.ViewGroup
 import android.widget.TextView
 import android.widget.Toast
-import androidx.databinding.DataBindingUtil
 import androidx.fragment.app.DialogFragment
 import info.nukoneko.cuc.android.kidspos.R
 import info.nukoneko.cuc.android.kidspos.databinding.FragmentCalculatorDialogBinding
@@ -57,13 +56,12 @@ class CalculatorDialogFragment : DialogFragment(), CoroutineScope {
         container: ViewGroup?,
         savedInstanceState: Bundle?
     ): View {
-        binding =
-            DataBindingUtil.inflate(inflater, R.layout.fragment_calculator_dialog, container, false)
-        binding.lifecycleOwner = this
+        binding = FragmentCalculatorDialogBinding.inflate(inflater, container, false)
         setupNumberPanel()
         myViewModel.listener = listener
         myViewModel.setup(items, totalPrice)
-        binding.viewModel = myViewModel
+        setupViewModelObservers()
+        setupClickListeners()
         return binding.root
     }
 
@@ -96,6 +94,28 @@ class CalculatorDialogFragment : DialogFragment(), CoroutineScope {
         binding.calculatorLayout.delete.setOnClickListener { myViewModel.onClearClick() }
     }
 
+    private fun setupViewModelObservers() {
+        myViewModel.getTotalPriceText().observe(viewLifecycleOwner) { price ->
+            binding.sumRiver.text = price
+        }
+        myViewModel.getDepositText().observe(viewLifecycleOwner) { deposit ->
+            binding.receiveRiver.text = deposit
+        }
+        myViewModel.getAccountButtonEnabled().observe(viewLifecycleOwner) { enabled ->
+            binding.done.isEnabled = enabled
+            binding.done.isClickable = enabled
+        }
+    }
+
+    private fun setupClickListeners() {
+        binding.back.setOnClickListener {
+            myViewModel.onCancelClick(it)
+        }
+        binding.done.setOnClickListener {
+            myViewModel.onDoneClick(it)
+        }
+    }
+
     companion object {
         private const val EXTRA_SUM_RIVER = "sum_price"
         private const val EXTRA_SALE_ITEMS = "sales_model"
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListFragment.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListFragment.kt
index 8837a76..e385dd4 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListFragment.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListFragment.kt
@@ -5,7 +5,6 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import android.widget.Toast
-import androidx.databinding.DataBindingUtil
 import androidx.fragment.app.Fragment
 import androidx.recyclerview.widget.GridLayoutManager
 import androidx.recyclerview.widget.RecyclerView
@@ -50,13 +49,12 @@ class ItemListFragment : Fragment() {
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
-    ): View? {
-        binding = DataBindingUtil.inflate(inflater, R.layout.fragment_item_list, container, false)
-        binding.viewModel = myViewModel.also {
-            it.listener = listener
-        }
-        binding.lifecycleOwner = this
+    ): View {
+        binding = FragmentItemListBinding.inflate(inflater, container, false)
+        myViewModel.listener = listener
         setupList(binding.recyclerView)
+        setupViewModelObservers()
+        setupClickListeners()
         return binding.root
     }
 
@@ -80,6 +78,30 @@ class ItemListFragment : Fragment() {
         list.layoutManager = GridLayoutManager(list.context, 3)
     }
 
+    private fun setupViewModelObservers() {
+        myViewModel.getCurrentPriceText().observe(viewLifecycleOwner) { price ->
+            binding.priceView.text = price
+        }
+        myViewModel.getCurrentStaffText().observe(viewLifecycleOwner) { staff ->
+            binding.staffText.text = staff
+        }
+        myViewModel.getCurrentStaffVisibility().observe(viewLifecycleOwner) { visibility ->
+            binding.staffLayout.visibility = visibility
+        }
+        myViewModel.getAccountButtonEnabled().observe(viewLifecycleOwner) { enabled ->
+            binding.accountButton.isEnabled = enabled
+        }
+    }
+
+    private fun setupClickListeners() {
+        binding.clearButton.setOnClickListener {
+            myViewModel.onClickClear(it)
+        }
+        binding.accountButton.setOnClickListener {
+            myViewModel.onClickAccount(it)
+        }
+    }
+
     companion object {
         fun newInstance() = ItemListFragment()
     }
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/ItemStoreListContentViewModel.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/ItemStoreListContentViewModel.kt
index 2dc10b1..62597f0 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/ItemStoreListContentViewModel.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/ItemStoreListContentViewModel.kt
@@ -1,25 +1,4 @@
 package info.nukoneko.cuc.android.kidspos.ui.main.storelist
 
-import android.view.View
-import androidx.databinding.BaseObservable
-import androidx.databinding.Bindable
-import info.nukoneko.cuc.android.kidspos.entity.Store
-
-class ItemStoreListContentViewModel(private var store: Store, private val listener: Listener?) :
-    BaseObservable() {
-    @Bindable
-    val storeName = store.name
-
-    fun onItemClick(@Suppress("UNUSED_PARAMETER") view: View?) {
-        listener?.onStoreSelected(store)
-    }
-
-    fun setStore(store: Store) {
-        this.store = store
-        notifyChange()
-    }
-
-    interface Listener {
-        fun onStoreSelected(store: Store)
-    }
-}
+// This file is kept empty to avoid breaking the build
+// It was previously used for Data Binding but is no longer needed after migration to View Binding
\ No newline at end of file
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListDialogFragment.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListDialogFragment.kt
index 7284676..ffe635e 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListDialogFragment.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListDialogFragment.kt
@@ -5,7 +5,6 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import android.widget.Toast
-import androidx.databinding.DataBindingUtil
 import androidx.fragment.app.DialogFragment
 import androidx.recyclerview.widget.DividerItemDecoration
 import androidx.recyclerview.widget.LinearLayoutManager
@@ -44,11 +43,8 @@ class StoreListDialogFragment : DialogFragment() {
         container: ViewGroup?,
         savedInstanceState: Bundle?
     ): View {
-        binding =
-            DataBindingUtil.inflate(inflater, R.layout.fragment_store_list_dialog, container, false)
-        binding.lifecycleOwner = this
+        binding = FragmentStoreListDialogBinding.inflate(inflater, container, false)
         myViewModel.listener = listener
-        binding.viewModel = myViewModel
         return binding.root
     }
 
@@ -60,6 +56,8 @@ class StoreListDialogFragment : DialogFragment() {
         )
         setupRecyclerView()
         setupSubscriber()
+        setupViewModelObservers()
+        setupClickListeners()
     }
 
     override fun onResume() {
@@ -85,6 +83,27 @@ class StoreListDialogFragment : DialogFragment() {
         })
     }
 
+    private fun setupViewModelObservers() {
+        myViewModel.getProgressVisibility().observe(viewLifecycleOwner) { visibility ->
+            binding.progressBar.visibility = visibility
+        }
+        myViewModel.getRecyclerViewVisibility().observe(viewLifecycleOwner) { visibility ->
+            binding.recyclerView.visibility = visibility
+        }
+        myViewModel.getErrorButtonVisibility().observe(viewLifecycleOwner) { visibility ->
+            binding.bottomView.visibility = visibility
+        }
+    }
+
+    private fun setupClickListeners() {
+        binding.reloadButton.setOnClickListener {
+            myViewModel.onReload(it)
+        }
+        binding.closeButton.setOnClickListener {
+            myViewModel.onClose(it)
+        }
+    }
+
     companion object {
         fun newInstance(): StoreListDialogFragment = StoreListDialogFragment()
     }
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListViewAdapter.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListViewAdapter.kt
index 65cc123..1344aac 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListViewAdapter.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListViewAdapter.kt
@@ -2,10 +2,9 @@ package info.nukoneko.cuc.android.kidspos.ui.main.storelist
 
 import android.view.LayoutInflater
 import android.view.ViewGroup
-import androidx.databinding.DataBindingUtil
 import androidx.recyclerview.widget.RecyclerView
 import info.nukoneko.cuc.android.kidspos.R
-import info.nukoneko.cuc.android.kidspos.databinding.ItemStoreListBinding
+import android.widget.TextView
 import info.nukoneko.cuc.android.kidspos.entity.Store
 
 class StoreListViewAdapter : RecyclerView.Adapter<StoreListViewAdapter.ViewHolder>() {
@@ -14,15 +13,9 @@ class StoreListViewAdapter : RecyclerView.Adapter<StoreListViewAdapter.ViewHolde
     var listener: Listener? = null
 
     override fun onCreateViewHolder(viewGroup: ViewGroup, i: Int): ViewHolder {
-        val binding = DataBindingUtil.inflate<ItemStoreListBinding>(
-            LayoutInflater.from(viewGroup.context),
-            R.layout.item_store_list, viewGroup, false
-        )
-        return ViewHolder(binding, object : ViewHolder.Listener {
-            override fun onItemClick(store: Store) {
-                listener?.onStoreSelect(store)
-            }
-        })
+        val view = LayoutInflater.from(viewGroup.context)
+            .inflate(R.layout.item_store_list, viewGroup, false) as TextView
+        return ViewHolder(view, listener)
     }
 
     override fun onBindViewHolder(holder: ViewHolder, position: Int) {
@@ -37,28 +30,22 @@ class StoreListViewAdapter : RecyclerView.Adapter<StoreListViewAdapter.ViewHolde
         fun onStoreSelect(store: Store)
     }
 
-    class ViewHolder(private val binding: ItemStoreListBinding, listener: Listener?) :
-        RecyclerView.ViewHolder(binding.item) {
-        private val listener: ItemStoreListContentViewModel.Listener
+    class ViewHolder(private val textView: TextView, private val listener: Listener?) :
+        RecyclerView.ViewHolder(textView) {
+        
+        private var currentStore: Store? = null
 
         init {
-            this.listener = object : ItemStoreListContentViewModel.Listener {
-                override fun onStoreSelected(store: Store) {
-                    listener?.onItemClick(store)
+            textView.setOnClickListener {
+                currentStore?.let { store ->
+                    listener?.onStoreSelect(store)
                 }
             }
         }
 
         fun bind(store: Store) {
-            if (binding.viewModel == null) {
-                binding.viewModel = ItemStoreListContentViewModel(store, listener)
-            } else {
-                binding.viewModel!!.setStore(store)
-            }
-        }
-
-        interface Listener {
-            fun onItemClick(store: Store)
+            currentStore = store
+            textView.text = store.name
         }
     }
 }
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/setting/SettingActivity.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/setting/SettingActivity.kt
index cd3149f..5080483 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/setting/SettingActivity.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/setting/SettingActivity.kt
@@ -4,13 +4,26 @@ import android.content.Context
 import android.content.Intent
 import android.os.Bundle
 import android.webkit.URLUtil
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
-import com.google.zxing.integration.android.IntentIntegrator
+import com.journeyapps.barcodescanner.ScanContract
+import com.journeyapps.barcodescanner.ScanOptions
 import info.nukoneko.cuc.android.kidspos.di.GlobalConfig
 import org.koin.android.ext.android.inject
 
 class SettingActivity : AppCompatActivity() {
     private val config: GlobalConfig by inject()
+    
+    private val barcodeLauncher = registerForActivityResult(
+        ScanContract()
+    ) { result ->
+        if (result.contents != null) {
+            val serverAddress = result.contents
+            if (URLUtil.isValidUrl(serverAddress)) {
+                config.currentServerAddress = serverAddress
+            }
+        }
+    }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -19,17 +32,15 @@ class SettingActivity : AppCompatActivity() {
             .replace(android.R.id.content, SettingFragment.newInstance())
             .commit()
     }
-
-    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
-        val result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data)
-        if (result != null) {
-            val serverAddress = result.contents
-            if (URLUtil.isValidUrl(serverAddress)) {
-                config.currentServerAddress = serverAddress
-            }
-        } else {
-            super.onActivityResult(requestCode, resultCode, data)
-        }
+    
+    fun launchBarcodeScanner() {
+        val options = ScanOptions()
+        options.setDesiredBarcodeFormats(ScanOptions.QR_CODE)
+        options.setPrompt("QRコードをスキャンしてください")
+        options.setCameraId(0)
+        options.setBeepEnabled(false)
+        options.setBarcodeImageEnabled(true)
+        barcodeLauncher.launch(options)
     }
 
     companion object {
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/setting/SettingFragment.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/setting/SettingFragment.kt
index 8d654e7..e0c995b 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/setting/SettingFragment.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/setting/SettingFragment.kt
@@ -6,7 +6,6 @@ import android.view.View
 import android.view.ViewGroup
 import android.widget.Toast
 import androidx.fragment.app.Fragment
-import com.google.zxing.integration.android.IntentIntegrator
 import info.nukoneko.cuc.android.kidspos.databinding.FragmentSettingBinding
 import info.nukoneko.cuc.android.kidspos.di.GlobalConfig
 import info.nukoneko.cuc.android.kidspos.util.Mode
@@ -51,7 +50,7 @@ class SettingFragment : Fragment() {
 
     private fun launchQrReader() {
         if (activity is SettingActivity) {
-            IntentIntegrator(activity).initiateScan()
+            (activity as SettingActivity).launchBarcodeScanner()
         }
     }
 
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/util/BarcodeKind.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/util/BarcodeKind.kt
index 816f758..afdf4d3 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/util/BarcodeKind.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/util/BarcodeKind.kt
@@ -17,4 +17,4 @@ enum class BarcodeKind(val prefix: String) {
         }
     }
 }
-//1001000000
\ No newline at end of file
+//1001000000
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/util/Mode.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/util/Mode.kt
index ffad181..cf14949 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/util/Mode.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/util/Mode.kt
@@ -8,4 +8,4 @@ enum class Mode(val modeName: String) {
             return values().singleOrNull { it.name == name } ?: PRACTICE
         }
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/res/drawable/frame_round_white.xml b/app/src/main/res/drawable/frame_round_white.xml
index 2d13cc4..66a8ea8 100644
--- a/app/src/main/res/drawable/frame_round_white.xml
+++ b/app/src/main/res/drawable/frame_round_white.xml
@@ -2,4 +2,4 @@
 <shape xmlns:android="http://schemas.android.com/apk/res/android">
     <corners android:radius="16dp" />
     <solid android:color="#FFFFFF" />
-</shape>
\ No newline at end of file
+</shape>
diff --git a/app/src/main/res/drawable/icon_circle.xml b/app/src/main/res/drawable/icon_circle.xml
index 985fcb6..370812e 100644
--- a/app/src/main/res/drawable/icon_circle.xml
+++ b/app/src/main/res/drawable/icon_circle.xml
@@ -5,4 +5,4 @@
     <stroke
         android:width="2dp"
         android:color="#EECCEE" />
-</shape>
\ No newline at end of file
+</shape>
diff --git a/app/src/main/res/drawable/layout_button_rect_red.xml b/app/src/main/res/drawable/layout_button_rect_red.xml
index c0bd2e0..cb9d58b 100644
--- a/app/src/main/res/drawable/layout_button_rect_red.xml
+++ b/app/src/main/res/drawable/layout_button_rect_red.xml
@@ -5,4 +5,4 @@
     <stroke
         android:width="2dp"
         android:color="#FFFFFF" />
-</shape>
\ No newline at end of file
+</shape>
diff --git a/app/src/main/res/drawable/layout_button_rect_white.xml b/app/src/main/res/drawable/layout_button_rect_white.xml
index 657355f..6f86049 100644
--- a/app/src/main/res/drawable/layout_button_rect_white.xml
+++ b/app/src/main/res/drawable/layout_button_rect_white.xml
@@ -5,4 +5,4 @@
     <stroke
         android:width="2dp"
         android:color="#AA88AA" />
-</shape>
\ No newline at end of file
+</shape>
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index eadcd24..c54591a 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,16 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
-<layout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.drawerlayout.widget.DrawerLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools">
-
-    <data>
-
-        <variable
-            name="viewModel"
-            type="info.nukoneko.cuc.android.kidspos.ui.main.MainViewModel" />
-    </data>
-
-    <androidx.drawerlayout.widget.DrawerLayout
+    xmlns:tools="http://schemas.android.com/tools"
         android:id="@+id/drawer_layout"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
@@ -53,5 +45,4 @@
             app:headerLayout="@layout/nav_header_main"
             app:menu="@menu/activity_main_drawer" />
 
-    </androidx.drawerlayout.widget.DrawerLayout>
-</layout>
\ No newline at end of file
+</androidx.drawerlayout.widget.DrawerLayout>
diff --git a/app/src/main/res/layout/fragment_calculator_dialog.xml b/app/src/main/res/layout/fragment_calculator_dialog.xml
index e965a06..68b4a48 100644
--- a/app/src/main/res/layout/fragment_calculator_dialog.xml
+++ b/app/src/main/res/layout/fragment_calculator_dialog.xml
@@ -1,17 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
-<layout xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
-    tools:ignore="UnusedAttribute">
-
-    <data>
-
-        <variable
-            name="viewModel"
-            type="info.nukoneko.cuc.android.kidspos.ui.main.calculate.CalculatorDialogViewModel" />
-    </data>
-
-    <LinearLayout
+    tools:ignore="UnusedAttribute"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_gravity="center"
@@ -68,7 +60,7 @@
                         android:gravity="center_vertical|end"
                         android:inputType="none"
                         android:maxLines="1"
-                        android:text="@{viewModel.totalPriceText}"
+                        tools:text="0"
                         android:textStyle="bold"
                         app:autoSizeTextType="uniform" />
                 </LinearLayout>
@@ -99,7 +91,7 @@
                         android:clickable="false"
                         android:gravity="center_vertical|end"
                         android:maxLines="1"
-                        android:text="@{viewModel.depositText}"
+                        tools:text="0"
                         android:textStyle="bold"
                         app:autoSizeTextType="uniform" />
                 </LinearLayout>
@@ -119,7 +111,6 @@
                     android:layout_weight="0.5"
                     android:autoSizeTextType="uniform"
                     android:maxLines="1"
-                    android:onClick="@{viewModel::onCancelClick}"
                     android:paddingTop="16dp"
                     android:paddingBottom="22dp"
                     android:text="@string/go_back"
@@ -133,15 +124,13 @@
                     android:layout_gravity="end|bottom"
                     android:layout_weight="0.5"
                     android:autoSizeTextType="uniform"
-                    android:clickable="@{viewModel.accountButtonEnabled}"
-                    android:enabled="@{viewModel.accountButtonEnabled}"
+                    android:clickable="false"
+                    android:enabled="false"
                     android:maxLines="1"
-                    android:onClick="@{viewModel::onDoneClick}"
                     android:paddingTop="16dp"
                     android:paddingBottom="22dp"
                     android:text="@string/account"
                     app:autoSizeTextType="uniform" />
             </LinearLayout>
         </LinearLayout>
-    </LinearLayout>
-</layout>
+</LinearLayout>
diff --git a/app/src/main/res/layout/fragment_item_list.xml b/app/src/main/res/layout/fragment_item_list.xml
index bf19bb1..70a6634 100644
--- a/app/src/main/res/layout/fragment_item_list.xml
+++ b/app/src/main/res/layout/fragment_item_list.xml
@@ -1,16 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
-<layout xmlns:android="http://schemas.android.com/apk/res/android"
+<RelativeLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools">
-
-    <data>
-
-        <variable
-            name="viewModel"
-            type="info.nukoneko.cuc.android.kidspos.ui.main.itemlist.ItemListViewModel" />
-    </data>
-
-    <RelativeLayout
+    xmlns:tools="http://schemas.android.com/tools"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="?attr/actionBarSize"
@@ -25,7 +17,7 @@
             android:background="#E0E0E0"
             android:gravity="end"
             android:padding="8dp"
-            android:text="@{viewModel.currentPriceText}"
+            tools:text="0 リバー"
             android:textSize="24sp" />
 
         <LinearLayout
@@ -42,7 +34,7 @@
                 android:layout_margin="4dp"
                 android:background="@drawable/layout_button_rect_red"
                 android:maxLines="1"
-                android:onClick="@{viewModel::onClickClear}"
+                android:id="@+id/clear_button"
                 android:text="@string/delete"
                 android:textColor="@android:color/white"
                 android:textSize="22sp" />
@@ -53,7 +45,8 @@
                 android:layout_margin="4dp"
                 android:layout_weight="1"
                 android:orientation="vertical"
-                android:visibility="@{viewModel.currentStaffVisibility}">
+                android:id="@+id/staff_layout"
+                android:visibility="invisible">
 
                 <TextView
                     android:layout_width="match_parent"
@@ -61,7 +54,8 @@
                     android:layout_weight="0.6"
                     android:gravity="center_vertical"
                     android:maxLines="1"
-                    android:text='@{viewModel.currentStaffText}' />
+                    android:id="@+id/staff_text"
+                    tools:text="たんとう:" />
             </LinearLayout>
 
             <Button
@@ -70,9 +64,9 @@
                 android:layout_height="match_parent"
                 android:layout_margin="4dp"
                 android:background="@drawable/layout_button_rect_white"
-                android:enabled="@{viewModel.accountButtonEnabled}"
+                android:id="@+id/account_button"
+                android:enabled="false"
                 android:maxLines="1"
-                android:onClick="@{viewModel::onClickAccount}"
                 android:paddingStart="16dp"
                 android:paddingEnd="16dp"
                 android:text="@string/account"
@@ -86,5 +80,4 @@
             android:layout_above="@id/bottom_layout"
             android:layout_below="@id/price_view"
             android:background="#303030" />
-    </RelativeLayout>
-</layout>
\ No newline at end of file
+</RelativeLayout>
diff --git a/app/src/main/res/layout/fragment_setting.xml b/app/src/main/res/layout/fragment_setting.xml
index 98ba0fe..8246c88 100644
--- a/app/src/main/res/layout/fragment_setting.xml
+++ b/app/src/main/res/layout/fragment_setting.xml
@@ -84,4 +84,4 @@
             android:textSize="28sp"
             tools:ignore="UnusedAttribute" />
     </LinearLayout>
-</ScrollView>
\ No newline at end of file
+</ScrollView>
diff --git a/app/src/main/res/layout/fragment_store_list_dialog.xml b/app/src/main/res/layout/fragment_store_list_dialog.xml
index 801fd11..2c11cc4 100644
--- a/app/src/main/res/layout/fragment_store_list_dialog.xml
+++ b/app/src/main/res/layout/fragment_store_list_dialog.xml
@@ -1,14 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
-<layout xmlns:app="http://schemas.android.com/apk/res-auto">
-
-    <data>
-
-        <variable
-            name="viewModel"
-            type="info.nukoneko.cuc.android.kidspos.ui.main.storelist.StoreListViewModel" />
-    </data>
-
-    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout 
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_margin="8dp"
@@ -19,7 +12,8 @@
             android:layout_height="wrap_content"
             android:layout_gravity="center"
             android:layout_margin="16dp"
-            app:visibility="@{viewModel.progressVisibility}" />
+            android:id="@+id/progress_bar"
+            android:visibility="visible" />
 
         <LinearLayout
             android:layout_width="match_parent"
@@ -31,7 +25,7 @@
                 android:layout_width="match_parent"
                 android:layout_height="0dp"
                 android:layout_weight="1"
-                app:visibility="@{viewModel.recyclerViewVisibility}" />
+                android:visibility="gone" />
 
             <LinearLayout
                 android:id="@+id/bottom_view"
@@ -39,7 +33,7 @@
                 android:layout_height="wrap_content"
                 android:layout_gravity="bottom"
                 android:orientation="horizontal"
-                app:visibility="@{viewModel.errorButtonVisibility}">
+                android:visibility="gone">
 
                 <Button
                     style="?android:actionButtonStyle"
@@ -47,7 +41,7 @@
                     android:layout_height="wrap_content"
                     android:layout_margin="8dp"
                     android:layout_weight="1"
-                    android:onClick="@{viewModel::onReload}"
+                    android:id="@+id/reload_button"
                     android:text="@string/reload" />
 
                 <Button
@@ -56,10 +50,9 @@
                     android:layout_height="wrap_content"
                     android:layout_margin="8dp"
                     android:layout_weight="1"
-                    android:onClick="@{viewModel::onClose}"
+                    android:id="@+id/close_button"
                     android:text="@string/close" />
             </LinearLayout>
         </LinearLayout>
 
-    </FrameLayout>
-</layout>
+</FrameLayout>
diff --git a/app/src/main/res/layout/item_store_list.xml b/app/src/main/res/layout/item_store_list.xml
index 8525cd3..0f1fcbb 100644
--- a/app/src/main/res/layout/item_store_list.xml
+++ b/app/src/main/res/layout/item_store_list.xml
@@ -1,22 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
-<layout xmlns:android="http://schemas.android.com/apk/res/android">
-
-    <data>
-
-        <variable
-            name="viewModel"
-            type="info.nukoneko.cuc.android.kidspos.ui.main.storelist.ItemStoreListContentViewModel" />
-    </data>
-
-    <TextView
+<TextView
+    xmlns:android="http://schemas.android.com/apk/res/android"
         android:id="@+id/item"
         style="?android:attr/selectableItemBackground"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_margin="8dp"
         android:gravity="center"
-        android:onClick="@{viewModel::onItemClick}"
         android:padding="8dp"
-        android:text="@{viewModel.storeName}"
         android:textSize="32sp" />
-</layout>
\ No newline at end of file
diff --git a/app/src/main/res/values/attrs.xml b/app/src/main/res/values/attrs.xml
index 9ef7b4b..5541074 100644
--- a/app/src/main/res/values/attrs.xml
+++ b/app/src/main/res/values/attrs.xml
@@ -3,4 +3,4 @@
     <declare-styleable name="CalculatorView">
         <attr name="number" format="integer" />
     </declare-styleable>
-</resources>
\ No newline at end of file
+</resources>
diff --git a/app/src/main/res/values/dimens.xml b/app/src/main/res/values/dimens.xml
index f655768..68f037f 100644
--- a/app/src/main/res/values/dimens.xml
+++ b/app/src/main/res/values/dimens.xml
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <dimen name="nav_header_height">120dp</dimen>
-</resources>
\ No newline at end of file
+</resources>
diff --git a/app/src/prod/kotlin/info/nukoneko/cuc/android/kidspos/ProjectSettings.kt b/app/src/prod/kotlin/info/nukoneko/cuc/android/kidspos/ProjectSettings.kt
index b0979c2..c625f04 100644
--- a/app/src/prod/kotlin/info/nukoneko/cuc/android/kidspos/ProjectSettings.kt
+++ b/app/src/prod/kotlin/info/nukoneko/cuc/android/kidspos/ProjectSettings.kt
@@ -2,4 +2,4 @@ package info.nukoneko.cuc.android.kidspos
 
 object ProjectSettings {
     const val DEMO_MODE = false
-}
\ No newline at end of file
+}
diff --git a/app/src/release/res/values/strings.xml b/app/src/release/res/values/strings.xml
index 06dfa5b..c80d5c3 100644
--- a/app/src/release/res/values/strings.xml
+++ b/app/src/release/res/values/strings.xml
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string name="app_name">KidsPOS</string>
-</resources>
\ No newline at end of file
+</resources>
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/api/APIServiceTest.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/api/APIServiceTest.kt
new file mode 100644
index 0000000..88f30fc
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/api/APIServiceTest.kt
@@ -0,0 +1,181 @@
+package info.nukoneko.cuc.android.kidspos.api
+
+import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
+import info.nukoneko.cuc.android.kidspos.entity.Item
+import info.nukoneko.cuc.android.kidspos.entity.Sale
+import info.nukoneko.cuc.android.kidspos.entity.Staff
+import info.nukoneko.cuc.android.kidspos.entity.Store
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.OkHttpClient
+import okhttp3.mockwebserver.MockResponse
+import okhttp3.mockwebserver.MockWebServer
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import retrofit2.HttpException
+import retrofit2.Retrofit
+import java.util.concurrent.TimeUnit
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+import kotlin.test.assertNotNull
+import kotlin.test.assertTrue
+
+@ExperimentalCoroutinesApi
+class APIServiceTest {
+    
+    private lateinit var mockWebServer: MockWebServer
+    private lateinit var apiService: APIService
+    private val json = Json { ignoreUnknownKeys = true }
+    
+    @Before
+    fun setup() {
+        mockWebServer = MockWebServer()
+        mockWebServer.start()
+        
+        val client = OkHttpClient.Builder()
+            .connectTimeout(1, TimeUnit.SECONDS)
+            .readTimeout(1, TimeUnit.SECONDS)
+            .writeTimeout(1, TimeUnit.SECONDS)
+            .build()
+        
+        val retrofit = Retrofit.Builder()
+            .baseUrl(mockWebServer.url("/"))
+            .client(client)
+            .addConverterFactory(json.asConverterFactory("application/json".toMediaType()))
+            .build()
+        
+        apiService = retrofit.create(APIService::class.java)
+    }
+    
+    @After
+    fun tearDown() {
+        mockWebServer.shutdown()
+    }
+    
+    @Test
+    fun `getItemByBarcode should return item on success`() = runTest {
+        // Given
+        val barcode = "1234567890"
+        val expectedItem = Item(barcode, "テスト商品", 500)
+        val jsonResponse = json.encodeToString(expectedItem)
+        mockWebServer.enqueue(MockResponse().setBody(jsonResponse).setResponseCode(200))
+        
+        // When
+        val result = apiService.getItemByBarcode(barcode)
+        
+        // Then
+        assertEquals(expectedItem.barcode, result.barcode)
+        assertEquals(expectedItem.name, result.name)
+        assertEquals(expectedItem.price, result.price)
+        
+        val request = mockWebServer.takeRequest()
+        assertEquals("GET", request.method)
+        assertEquals("/api/items/$barcode", request.path)
+    }
+    
+    @Test
+    fun `getItemByBarcode should throw HttpException on 404`() = runTest {
+        // Given
+        val barcode = "9999999999"
+        mockWebServer.enqueue(MockResponse().setResponseCode(404))
+        
+        // When/Then
+        val exception = assertFailsWith<HttpException> {
+            apiService.getItemByBarcode(barcode)
+        }
+        assertEquals(404, exception.code())
+    }
+    
+    @Test
+    fun `getStaffByBarcode should return staff on success`() = runTest {
+        // Given
+        val barcode = "100"
+        val expectedStaff = Staff(1, barcode, "テストスタッフ")
+        val jsonResponse = json.encodeToString(expectedStaff)
+        mockWebServer.enqueue(MockResponse().setBody(jsonResponse).setResponseCode(200))
+        
+        // When
+        val result = apiService.getStaffByBarcode(barcode)
+        
+        // Then
+        assertEquals(expectedStaff.id, result.id)
+        assertEquals(expectedStaff.barcode, result.barcode)
+        assertEquals(expectedStaff.name, result.name)
+        
+        val request = mockWebServer.takeRequest()
+        assertEquals("GET", request.method)
+        assertEquals("/api/staffs/$barcode", request.path)
+    }
+    
+    @Test
+    fun `getStores should return list of stores`() = runTest {
+        // Given
+        val stores = listOf(
+            Store(1, "店舗1"),
+            Store(2, "店舗2"),
+            Store(3, "店舗3")
+        )
+        val jsonResponse = json.encodeToString(stores)
+        mockWebServer.enqueue(MockResponse().setBody(jsonResponse).setResponseCode(200))
+        
+        // When
+        val result = apiService.getStores()
+        
+        // Then
+        assertEquals(3, result.size)
+        assertEquals("店舗1", result[0].name)
+        assertEquals("店舗2", result[1].name)
+        assertEquals("店舗3", result[2].name)
+        
+        val request = mockWebServer.takeRequest()
+        assertEquals("GET", request.method)
+        assertEquals("/api/stores", request.path)
+    }
+    
+    @Test
+    fun `postSale should send sale data correctly`() = runTest {
+        // Given
+        val items = listOf(
+            Item("123", "商品1", 100),
+            Item("456", "商品2", 200)
+        )
+        val sale = Sale("20240101120000", 1, 1, items, 300)
+        val expectedResponse = mapOf("status" to "success")
+        val jsonResponse = json.encodeToString(expectedResponse)
+        mockWebServer.enqueue(MockResponse().setBody(jsonResponse).setResponseCode(201))
+        
+        // When
+        val result = apiService.postSale(sale)
+        
+        // Then
+        assertNotNull(result)
+        
+        val request = mockWebServer.takeRequest()
+        assertEquals("POST", request.method)
+        assertEquals("/api/sales", request.path)
+        
+        val requestBody = request.body.readUtf8()
+        assertTrue(requestBody.contains("20240101120000"))
+        assertTrue(requestBody.contains("商品1"))
+        assertTrue(requestBody.contains("商品2"))
+    }
+    
+    @Test
+    fun `network timeout should throw exception`() = runTest {
+        // Given
+        mockWebServer.enqueue(
+            MockResponse()
+                .setResponseCode(200)
+                .setBodyDelay(2, TimeUnit.SECONDS)
+        )
+        
+        // When/Then
+        assertFailsWith<Exception> {
+            apiService.getStores()
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/CoroutineTestRule.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/CoroutineTestRule.kt
new file mode 100644
index 0000000..4132865
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/CoroutineTestRule.kt
@@ -0,0 +1,30 @@
+package info.nukoneko.cuc.android.kidspos.testutil
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.TestDispatcher
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.setMain
+import org.junit.rules.TestWatcher
+import org.junit.runner.Description
+
+/**
+ * JUnit rule that sets the Main dispatcher to a test dispatcher before the test starts
+ * and resets it after the test finishes.
+ */
+@ExperimentalCoroutinesApi
+class CoroutineTestRule(
+    val testDispatcher: TestDispatcher = UnconfinedTestDispatcher()
+) : TestWatcher() {
+
+    override fun starting(description: Description) {
+        super.starting(description)
+        Dispatchers.setMain(testDispatcher)
+    }
+
+    override fun finished(description: Description) {
+        super.finished(description)
+        Dispatchers.resetMain()
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/FakeEventBus.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/FakeEventBus.kt
new file mode 100644
index 0000000..cc5b372
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/FakeEventBus.kt
@@ -0,0 +1,38 @@
+package info.nukoneko.cuc.android.kidspos.testutil
+
+import info.nukoneko.cuc.android.kidspos.event.Event
+import info.nukoneko.cuc.android.kidspos.event.EventBus
+
+/**
+ * Fake implementation of EventBus for testing
+ */
+class FakeEventBus : EventBus {
+    private val events = mutableListOf<Event>()
+    private val subscribers = mutableListOf<Any>()
+    
+    override fun register(obj: Any?) {
+        obj?.let { subscribers.add(it) }
+    }
+    
+    override fun unregister(obj: Any?) {
+        obj?.let { subscribers.remove(it) }
+    }
+    
+    override fun post(event: Event) {
+        events.add(event)
+    }
+    
+    fun getPostedEvents(): List<Event> = events.toList()
+    
+    fun clearEvents() {
+        events.clear()
+    }
+    
+    fun hasPostedEvent(predicate: (Event) -> Boolean): Boolean {
+        return events.any(predicate)
+    }
+    
+    fun getLastPostedEvent(): Event? = events.lastOrNull()
+    
+    fun isRegistered(obj: Any): Boolean = subscribers.contains(obj)
+}
\ No newline at end of file
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/FakeGlobalConfig.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/FakeGlobalConfig.kt
new file mode 100644
index 0000000..bdba2bb
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/FakeGlobalConfig.kt
@@ -0,0 +1,57 @@
+package info.nukoneko.cuc.android.kidspos.testutil
+
+import info.nukoneko.cuc.android.kidspos.di.GlobalConfig
+import info.nukoneko.cuc.android.kidspos.entity.Staff
+import info.nukoneko.cuc.android.kidspos.entity.Store
+import info.nukoneko.cuc.android.kidspos.util.Mode
+
+/**
+ * Fake implementation of GlobalConfig for testing
+ */
+class FakeGlobalConfig : GlobalConfig {
+    private var _currentStore: Store? = null
+    private var _currentStaff: Staff? = null
+    private var _currentServerAddress: String = "http://localhost:8080"
+    private var _currentRunningMode: Mode = Mode.PRACTICE
+    
+    override var currentStore: Store?
+        get() = _currentStore
+        set(value) {
+            _currentStore = value
+        }
+    
+    override var currentStaff: Staff?
+        get() = _currentStaff
+        set(value) {
+            _currentStaff = value
+        }
+    
+    override var currentServerAddress: String
+        get() = _currentServerAddress
+        set(value) {
+            _currentServerAddress = value
+        }
+    
+    override var currentRunningMode: Mode
+        get() = _currentRunningMode
+        set(value) {
+            _currentRunningMode = value
+        }
+    
+    // Test helper methods
+    fun setTestStore(store: Store?) {
+        _currentStore = store
+    }
+    
+    fun setTestStaff(staff: Staff?) {
+        _currentStaff = staff
+    }
+    
+    fun setTestServerAddress(address: String) {
+        _currentServerAddress = address
+    }
+    
+    fun setTestRunningMode(mode: Mode) {
+        _currentRunningMode = mode
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/LiveDataTestUtil.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/LiveDataTestUtil.kt
new file mode 100644
index 0000000..de109d9
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/testutil/LiveDataTestUtil.kt
@@ -0,0 +1,60 @@
+package info.nukoneko.cuc.android.kidspos.testutil
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Observer
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+import java.util.concurrent.TimeoutException
+
+/**
+ * Gets the value of a [LiveData] or waits for it to have one, with a timeout.
+ *
+ * Use this extension from host-side (JVM) tests. Never use it from device-side (instrumented) tests.
+ *
+ * [getOrAwaitValue] is a synchronous call. If the LiveData already has a value, it returns it immediately.
+ * If not, it waits for the value to be set before returning it.
+ */
+fun <T> LiveData<T>.getOrAwaitValue(
+    time: Long = 2,
+    timeUnit: TimeUnit = TimeUnit.SECONDS,
+    afterObserve: () -> Unit = {}
+): T {
+    var data: T? = null
+    val latch = CountDownLatch(1)
+    val observer = object : Observer<T> {
+        override fun onChanged(value: T) {
+            data = value
+            latch.countDown()
+            this@getOrAwaitValue.removeObserver(this)
+        }
+    }
+    this.observeForever(observer)
+
+    try {
+        afterObserve.invoke()
+
+        // Don't wait indefinitely if the LiveData is not set.
+        if (!latch.await(time, timeUnit)) {
+            this.removeObserver(observer)
+            throw TimeoutException("LiveData value was never set.")
+        }
+    } finally {
+        this.removeObserver(observer)
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    return data as T
+}
+
+/**
+ * Observes a [LiveData] until the `block` is done executing.
+ */
+fun <T> LiveData<T>.observeForTesting(block: () -> Unit) {
+    val observer = Observer<T> { }
+    try {
+        observeForever(observer)
+        block()
+    } finally {
+        removeObserver(observer)
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/ItemListViewModelTest.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/ItemListViewModelTest.kt
new file mode 100644
index 0000000..a4dc160
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/ItemListViewModelTest.kt
@@ -0,0 +1,170 @@
+package info.nukoneko.cuc.android.kidspos.ui.main
+
+import android.view.View
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import info.nukoneko.cuc.android.kidspos.entity.Item
+import info.nukoneko.cuc.android.kidspos.entity.Staff
+import info.nukoneko.cuc.android.kidspos.event.BarcodeEvent
+import info.nukoneko.cuc.android.kidspos.testutil.CoroutineTestRule
+import info.nukoneko.cuc.android.kidspos.testutil.FakeEventBus
+import info.nukoneko.cuc.android.kidspos.testutil.FakeGlobalConfig
+import info.nukoneko.cuc.android.kidspos.testutil.getOrAwaitValue
+import info.nukoneko.cuc.android.kidspos.ui.main.itemlist.ItemListViewModel
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.junit.MockitoJUnitRunner
+import org.mockito.kotlin.*
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+@ExperimentalCoroutinesApi
+@RunWith(MockitoJUnitRunner::class)
+class ItemListViewModelTest {
+    
+    @get:Rule
+    val instantTaskExecutorRule = InstantTaskExecutorRule()
+    
+    @get:Rule
+    val coroutineTestRule = CoroutineTestRule()
+    
+    private lateinit var viewModel: ItemListViewModel
+    private lateinit var fakeEventBus: FakeEventBus
+    private lateinit var fakeGlobalConfig: FakeGlobalConfig
+    private lateinit var mockListener: ItemListViewModel.Listener
+    
+    @Before
+    fun setup() {
+        fakeEventBus = FakeEventBus()
+        fakeGlobalConfig = FakeGlobalConfig()
+        mockListener = mock()
+        
+        viewModel = ItemListViewModel(fakeGlobalConfig, fakeEventBus)
+        viewModel.listener = mockListener
+    }
+    
+    @Test
+    fun `initial state should show zero price and disabled account button`() {
+        // Then
+        assertEquals("0 リバー", viewModel.getCurrentPriceText().getOrAwaitValue())
+        assertFalse(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onClickClear should clear items and notify listener`() {
+        // Given
+        val item = Item("123", "テスト商品", 100)
+        viewModel.onReadItemSuccessEvent(BarcodeEvent.ReadItemSuccess(item))
+        
+        // When
+        viewModel.onClickClear(null)
+        
+        // Then
+        verify(mockListener).onDataClear()
+        assertEquals("0 リバー", viewModel.getCurrentPriceText().getOrAwaitValue())
+        assertFalse(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onClickAccount should start account with current items`() {
+        // Given
+        val item1 = Item("123", "商品1", 100)
+        val item2 = Item("456", "商品2", 200)
+        viewModel.onReadItemSuccessEvent(BarcodeEvent.ReadItemSuccess(item1))
+        viewModel.onReadItemSuccessEvent(BarcodeEvent.ReadItemSuccess(item2))
+        
+        // When
+        viewModel.onClickAccount(null)
+        
+        // Then
+        argumentCaptor<List<Item>>().apply {
+            verify(mockListener).onStartAccount(capture())
+            assertEquals(2, firstValue.size)
+            assertEquals(item1, firstValue[0])
+            assertEquals(item2, firstValue[1])
+        }
+    }
+    
+    @Test
+    fun `staff visibility should be VISIBLE when staff is set`() {
+        // Given
+        val staff = Staff(1, "100", "テストスタッフ")
+        fakeGlobalConfig.setTestStaff(staff)
+        
+        // When
+        viewModel.onResume()
+        
+        // Then
+        assertEquals(View.VISIBLE, viewModel.getCurrentStaffVisibility().getOrAwaitValue())
+        assertEquals("たんとう: テストスタッフ", viewModel.getCurrentStaffText().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `staff visibility should be INVISIBLE when staff is not set`() {
+        // Given
+        fakeGlobalConfig.setTestStaff(null)
+        
+        // When
+        viewModel.onResume()
+        
+        // Then
+        assertEquals(View.INVISIBLE, viewModel.getCurrentStaffVisibility().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onReadItemSuccessEvent should add item and update views`() {
+        // Given
+        val item = Item("789", "テスト商品", 500)
+        val event = BarcodeEvent.ReadItemSuccess(item)
+        
+        // When
+        viewModel.onReadItemSuccessEvent(event)
+        
+        // Then
+        verify(mockListener).onDataAdded(item)
+        assertEquals("500 リバー", viewModel.getCurrentPriceText().getOrAwaitValue())
+        assertTrue(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `multiple items should calculate total correctly`() {
+        // Given
+        val item1 = Item("123", "商品1", 100)
+        val item2 = Item("456", "商品2", 200)
+        val item3 = Item("789", "商品3", 300)
+        
+        // When
+        viewModel.onReadItemSuccessEvent(BarcodeEvent.ReadItemSuccess(item1))
+        viewModel.onReadItemSuccessEvent(BarcodeEvent.ReadItemSuccess(item2))
+        viewModel.onReadItemSuccessEvent(BarcodeEvent.ReadItemSuccess(item3))
+        
+        // Then
+        assertEquals("600 リバー", viewModel.getCurrentPriceText().getOrAwaitValue())
+        assertTrue(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onStart should register to event bus`() {
+        // When
+        viewModel.onStart()
+        
+        // Then
+        assertTrue(fakeEventBus.isRegistered(viewModel))
+    }
+    
+    @Test
+    fun `onStop should unregister from event bus`() {
+        // Given
+        viewModel.onStart()
+        
+        // When
+        viewModel.onStop()
+        
+        // Then
+        assertFalse(fakeEventBus.isRegistered(viewModel))
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModelTest.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModelTest.kt
new file mode 100644
index 0000000..67286ae
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModelTest.kt
@@ -0,0 +1,166 @@
+package info.nukoneko.cuc.android.kidspos.ui.main
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import info.nukoneko.cuc.android.kidspos.entity.Item
+import info.nukoneko.cuc.android.kidspos.entity.Staff
+import info.nukoneko.cuc.android.kidspos.entity.Store
+import info.nukoneko.cuc.android.kidspos.event.BarcodeEvent
+import info.nukoneko.cuc.android.kidspos.event.SystemEvent
+import info.nukoneko.cuc.android.kidspos.testutil.CoroutineTestRule
+import info.nukoneko.cuc.android.kidspos.testutil.FakeEventBus
+import info.nukoneko.cuc.android.kidspos.testutil.FakeGlobalConfig
+import info.nukoneko.cuc.android.kidspos.util.BarcodeKind
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.junit.MockitoJUnitRunner
+import org.mockito.kotlin.*
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+import kotlin.test.assertTrue
+
+@ExperimentalCoroutinesApi
+@RunWith(MockitoJUnitRunner::class)
+class MainViewModelTest {
+    
+    @get:Rule
+    val instantTaskExecutorRule = InstantTaskExecutorRule()
+    
+    @get:Rule
+    val coroutineTestRule = CoroutineTestRule()
+    
+    private lateinit var viewModel: MainViewModel
+    private lateinit var fakeEventBus: FakeEventBus
+    private lateinit var fakeGlobalConfig: FakeGlobalConfig
+    private lateinit var mockListener: MainViewModel.Listener
+    
+    @Before
+    fun setup() {
+        fakeEventBus = FakeEventBus()
+        fakeGlobalConfig = FakeGlobalConfig()
+        mockListener = mock()
+        
+        viewModel = MainViewModel(fakeGlobalConfig, fakeEventBus)
+        viewModel.listener = mockListener
+    }
+    
+    @Test
+    fun `onStart should register to event bus`() {
+        // When
+        viewModel.onStart()
+        
+        // Then
+        assertTrue(fakeEventBus.isRegistered(viewModel))
+    }
+    
+    @Test
+    fun `onStop should unregister from event bus`() {
+        // Given
+        viewModel.onStart()
+        
+        // When
+        viewModel.onStop()
+        
+        // Then
+        assertTrue(!fakeEventBus.isRegistered(viewModel))
+    }
+    
+    @Test
+    fun `onResume should update title with store name when store is set`() {
+        // Given
+        val store = Store(1, "テスト店舗")
+        fakeGlobalConfig.setTestStore(store)
+        
+        // When
+        viewModel.onResume()
+        
+        // Then
+        verify(mockListener).onShouldChangeTitleSuffix("(テスト店舗)")
+    }
+    
+    @Test
+    fun `onBarcodeInput with ITEM barcode should post ReadItemRequest`() = runTest {
+        // Given
+        val barcode = "1234567890"
+        
+        // When
+        viewModel.onBarcodeInput(barcode, BarcodeKind.ITEM)
+        
+        // Then
+        val postedEvent = fakeEventBus.getLastPostedEvent()
+        assertNotNull(postedEvent)
+        assertTrue(postedEvent is BarcodeEvent.ReadItemRequest)
+        assertEquals(barcode, (postedEvent as BarcodeEvent.ReadItemRequest).barcode)
+    }
+    
+    @Test
+    fun `onBarcodeInput with STAFF barcode should post ReadStaffRequest`() = runTest {
+        // Given
+        val barcode = "9876543210"
+        
+        // When
+        viewModel.onBarcodeInput(barcode, BarcodeKind.STAFF)
+        
+        // Then
+        val postedEvent = fakeEventBus.getLastPostedEvent()
+        assertNotNull(postedEvent)
+        assertTrue(postedEvent is BarcodeEvent.ReadStaffRequest)
+        assertEquals(barcode, (postedEvent as BarcodeEvent.ReadStaffRequest).barcode)
+    }
+    
+    @Test
+    fun `onReadItemFailureEvent should show message when no server configured`() = runTest {
+        // Given
+        fakeGlobalConfig.setTestServerAddress("")
+        val event = BarcodeEvent.ReadItemFailure("1234567890", BarcodeEvent.ReadFailureType.NO_CONFIGURATION)
+        
+        // When
+        viewModel.onReadItemFailureEvent(event)
+        
+        // Then
+        verify(mockListener).onNotReachableServer()
+    }
+    
+    @Test
+    fun `onReadItemFailureEvent should show error message for network error`() = runTest {
+        // Given
+        val event = BarcodeEvent.ReadItemFailure("1234567890", BarcodeEvent.ReadFailureType.NETWORK_ERROR)
+        
+        // When
+        viewModel.onReadItemFailureEvent(event)
+        
+        // Then
+        verify(mockListener).onShouldShowMessage("通信に失敗しました。")
+    }
+    
+    @Test
+    fun `onReadStaffSuccessEvent should update global config and show message`() = runTest {
+        // Given
+        val staff = Staff(1, "100", "テストスタッフ")
+        val event = BarcodeEvent.ReadStaffSuccess(staff)
+        
+        // When
+        viewModel.onReadStaffSuccessEvent(event)
+        
+        // Then
+        assertEquals(staff, fakeGlobalConfig.currentStaff)
+        verify(mockListener).onShouldShowMessage("スタッフ ${staff.name} でログインしました")
+    }
+    
+    @Test
+    fun `onSystemStoreChangeEvent should update title`() = runTest {
+        // Given
+        val store = Store(2, "新店舗")
+        fakeGlobalConfig.setTestStore(store)
+        val event = SystemEvent.StoreChange(store)
+        
+        // When
+        viewModel.onSystemStoreChangeEvent(event)
+        
+        // Then
+        verify(mockListener).onShouldChangeTitleSuffix("(新店舗)")
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/calculate/CalculatorDialogViewModelTest.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/calculate/CalculatorDialogViewModelTest.kt
new file mode 100644
index 0000000..deed412
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/calculate/CalculatorDialogViewModelTest.kt
@@ -0,0 +1,302 @@
+package info.nukoneko.cuc.android.kidspos.ui.main.calculate
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import info.nukoneko.cuc.android.kidspos.api.APIService
+import info.nukoneko.cuc.android.kidspos.entity.Item
+import info.nukoneko.cuc.android.kidspos.entity.Sale
+import info.nukoneko.cuc.android.kidspos.entity.Staff
+import info.nukoneko.cuc.android.kidspos.entity.Store
+import info.nukoneko.cuc.android.kidspos.event.SystemEvent
+import info.nukoneko.cuc.android.kidspos.testutil.CoroutineTestRule
+import info.nukoneko.cuc.android.kidspos.testutil.FakeEventBus
+import info.nukoneko.cuc.android.kidspos.testutil.FakeGlobalConfig
+import info.nukoneko.cuc.android.kidspos.testutil.getOrAwaitValue
+import info.nukoneko.cuc.android.kidspos.util.Mode
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.junit.MockitoJUnitRunner
+import org.mockito.kotlin.*
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+@ExperimentalCoroutinesApi
+@RunWith(MockitoJUnitRunner::class)
+class CalculatorDialogViewModelTest {
+    
+    @get:Rule
+    val instantTaskExecutorRule = InstantTaskExecutorRule()
+    
+    @get:Rule
+    val coroutineTestRule = CoroutineTestRule()
+    
+    @Mock
+    private lateinit var mockApi: APIService
+    
+    private lateinit var viewModel: CalculatorDialogViewModel
+    private lateinit var fakeEventBus: FakeEventBus
+    private lateinit var fakeGlobalConfig: FakeGlobalConfig
+    private lateinit var mockListener: CalculatorDialogViewModel.Listener
+    
+    @Before
+    fun setup() {
+        fakeEventBus = FakeEventBus()
+        fakeGlobalConfig = FakeGlobalConfig()
+        mockListener = mock()
+        
+        viewModel = CalculatorDialogViewModel(mockApi, fakeGlobalConfig, fakeEventBus)
+        viewModel.listener = mockListener
+    }
+    
+    @Test
+    fun `initial state should have zero total price and disabled account button`() {
+        // Then
+        assertEquals("0", viewModel.getTotalPriceText().getOrAwaitValue())
+        assertEquals("0", viewModel.getDepositText().getOrAwaitValue())
+        assertFalse(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `setup should update total price and items`() {
+        // Given
+        val items = listOf(
+            Item("123", "商品1", 100),
+            Item("456", "商品2", 200)
+        )
+        val totalPrice = 300
+        
+        // When
+        viewModel.setup(items, totalPrice)
+        
+        // Then
+        assertEquals("300", viewModel.getTotalPriceText().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onNumberClick should update deposit and enable account button when sufficient`() {
+        // Given
+        viewModel.setup(listOf(Item("123", "商品", 500)), 500)
+        
+        // When
+        viewModel.onNumberClick(5)
+        
+        // Then
+        assertEquals("5", viewModel.getDepositText().getOrAwaitValue())
+        assertFalse(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+        
+        // When
+        viewModel.onNumberClick(0)
+        viewModel.onNumberClick(0)
+        
+        // Then
+        assertEquals("500", viewModel.getDepositText().getOrAwaitValue())
+        assertTrue(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onNumberClick should build multi-digit number correctly`() {
+        // When
+        viewModel.onNumberClick(1)
+        viewModel.onNumberClick(2)
+        viewModel.onNumberClick(3)
+        
+        // Then
+        assertEquals("123", viewModel.getDepositText().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onNumberClick should not exceed 100000`() {
+        // Given
+        viewModel.onNumberClick(9)
+        viewModel.onNumberClick(9)
+        viewModel.onNumberClick(9)
+        viewModel.onNumberClick(9)
+        viewModel.onNumberClick(9)
+        viewModel.onNumberClick(9) // 999999
+        
+        // When
+        viewModel.onNumberClick(9) // Should not add this
+        
+        // Then
+        assertEquals("999999", viewModel.getDepositText().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onClearClick should remove last digit`() {
+        // Given
+        viewModel.onNumberClick(1)
+        viewModel.onNumberClick(2)
+        viewModel.onNumberClick(3)
+        
+        // When
+        viewModel.onClearClick()
+        
+        // Then
+        assertEquals("12", viewModel.getDepositText().getOrAwaitValue())
+        
+        // When
+        viewModel.onClearClick()
+        
+        // Then
+        assertEquals("1", viewModel.getDepositText().getOrAwaitValue())
+        
+        // When
+        viewModel.onClearClick()
+        
+        // Then
+        assertEquals("0", viewModel.getDepositText().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onDoneClick should show result dialog`() {
+        // Given
+        viewModel.setup(listOf(Item("123", "商品", 500)), 500)
+        viewModel.onNumberClick(5)
+        viewModel.onNumberClick(0)
+        viewModel.onNumberClick(0)
+        
+        // When
+        viewModel.onDoneClick(null)
+        
+        // Then
+        verify(mockListener).onShouldShowResultDialog(500, 500)
+    }
+    
+    @Test
+    fun `onCancelClick should dismiss dialog`() {
+        // When
+        viewModel.onCancelClick(null)
+        
+        // Then
+        verify(mockListener).onDismiss()
+    }
+    
+    @Test
+    fun `onOk in practice mode should show message and dismiss without API call`() = runTest {
+        // Given
+        fakeGlobalConfig.setTestRunningMode(Mode.PRACTICE)
+        viewModel.setup(listOf(Item("123", "商品", 500)), 500)
+        
+        // When
+        viewModel.onOk()
+        
+        // Then
+        verify(mockListener).onShouldShowErrorMessage("練習モードのためレシートは出ません")
+        verify(mockListener).onDismiss()
+        verifyNoInteractions(mockApi)
+        
+        val event = fakeEventBus.getLastPostedEvent() as? SystemEvent.SentSaleSuccess
+        assertEquals(null, event?.sale)
+    }
+    
+    @Test
+    fun `onOk in normal mode should create sale via API`() = runTest {
+        // Given
+        fakeGlobalConfig.setTestRunningMode(Mode.REGISTER)
+        fakeGlobalConfig.setTestStore(Store(1, "テスト店舗"))
+        fakeGlobalConfig.setTestStaff(Staff(1, "100", "テストスタッフ"))
+        
+        val items = listOf(
+            Item("123", "商品1", 100),
+            Item("456", "商品2", 200)
+        )
+        viewModel.setup(items, 300)
+        viewModel.onNumberClick(5)
+        viewModel.onNumberClick(0)
+        viewModel.onNumberClick(0)
+        
+        val expectedSale = Sale("20240101120000", 1, 1, items, 300)
+        whenever(mockApi.createSale(1, "100", 500, "123,456")).thenReturn(expectedSale)
+        
+        // When
+        viewModel.onOk()
+        
+        // Then
+        verify(mockApi).createSale(1, "100", 500, "123,456")
+        verify(mockListener).onDismiss()
+        
+        val event = fakeEventBus.getLastPostedEvent() as? SystemEvent.SentSaleSuccess
+        assertEquals(expectedSale, event?.sale)
+    }
+    
+    @Test
+    fun `onOk should show error message when API fails`() = runTest {
+        // Given
+        fakeGlobalConfig.setTestRunningMode(Mode.REGISTER)
+        fakeGlobalConfig.setTestStore(Store(1, "テスト店舗"))
+        fakeGlobalConfig.setTestStaff(Staff(1, "100", "テストスタッフ"))
+        
+        viewModel.setup(listOf(Item("123", "商品", 500)), 500)
+        viewModel.onNumberClick(5)
+        viewModel.onNumberClick(0)
+        viewModel.onNumberClick(0)
+        
+        val exception = RuntimeException("Network error")
+        whenever(mockApi.createSale(any(), any(), any(), any())).thenThrow(exception)
+        
+        // When
+        viewModel.onOk()
+        
+        // Then
+        verify(mockListener).onShouldShowErrorMessage("Network error")
+        verify(mockListener, never()).onDismiss()
+    }
+    
+    @Test
+    fun `onOk with missing store or staff should use defaults`() = runTest {
+        // Given
+        fakeGlobalConfig.setTestRunningMode(Mode.REGISTER)
+        fakeGlobalConfig.setTestStore(null)
+        fakeGlobalConfig.setTestStaff(null)
+        
+        viewModel.setup(listOf(Item("123", "商品", 500)), 500)
+        viewModel.onNumberClick(5)
+        viewModel.onNumberClick(0)
+        viewModel.onNumberClick(0)
+        
+        val expectedSale = Sale("20240101120000", 0, 0, listOf(Item("123", "商品", 500)), 500)
+        whenever(mockApi.createSale(0, "", 500, "123")).thenReturn(expectedSale)
+        
+        // When
+        viewModel.onOk()
+        
+        // Then
+        verify(mockApi).createSale(0, "", 500, "123")
+    }
+    
+    @Test
+    fun `account button should be disabled when deposit is less than total`() {
+        // Given
+        viewModel.setup(listOf(Item("123", "商品", 1000)), 1000)
+        
+        // When
+        viewModel.onNumberClick(9)
+        viewModel.onNumberClick(9)
+        viewModel.onNumberClick(9)
+        
+        // Then
+        assertEquals("999", viewModel.getDepositText().getOrAwaitValue())
+        assertFalse(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `account button should be enabled when deposit equals total`() {
+        // Given
+        viewModel.setup(listOf(Item("123", "商品", 1000)), 1000)
+        
+        // When
+        viewModel.onNumberClick(1)
+        viewModel.onNumberClick(0)
+        viewModel.onNumberClick(0)
+        viewModel.onNumberClick(0)
+        
+        // Then
+        assertEquals("1000", viewModel.getDepositText().getOrAwaitValue())
+        assertTrue(viewModel.getAccountButtonEnabled().getOrAwaitValue())
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListViewModelTest.kt b/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListViewModelTest.kt
new file mode 100644
index 0000000..b777428
--- /dev/null
+++ b/app/src/test/java/info/nukoneko/cuc/android/kidspos/ui/main/storelist/StoreListViewModelTest.kt
@@ -0,0 +1,177 @@
+package info.nukoneko.cuc.android.kidspos.ui.main.storelist
+
+import android.view.View
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import info.nukoneko.cuc.android.kidspos.api.APIService
+import info.nukoneko.cuc.android.kidspos.entity.Store
+import info.nukoneko.cuc.android.kidspos.testutil.CoroutineTestRule
+import info.nukoneko.cuc.android.kidspos.testutil.FakeGlobalConfig
+import info.nukoneko.cuc.android.kidspos.testutil.getOrAwaitValue
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.junit.MockitoJUnitRunner
+import org.mockito.kotlin.*
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+@ExperimentalCoroutinesApi
+@RunWith(MockitoJUnitRunner::class)
+class StoreListViewModelTest {
+    
+    @get:Rule
+    val instantTaskExecutorRule = InstantTaskExecutorRule()
+    
+    @get:Rule
+    val coroutineTestRule = CoroutineTestRule()
+    
+    @Mock
+    private lateinit var mockApi: APIService
+    
+    private lateinit var viewModel: StoreListViewModel
+    private lateinit var fakeGlobalConfig: FakeGlobalConfig
+    private lateinit var mockListener: StoreListViewModel.Listener
+    
+    @Before
+    fun setup() {
+        fakeGlobalConfig = FakeGlobalConfig()
+        mockListener = mock()
+        
+        viewModel = StoreListViewModel(mockApi, fakeGlobalConfig)
+        viewModel.listener = mockListener
+    }
+    
+    @Test
+    fun `initial state should hide all views`() {
+        // Then
+        assertEquals(View.GONE, viewModel.getProgressVisibility().getOrAwaitValue())
+        assertEquals(View.GONE, viewModel.getRecyclerViewVisibility().getOrAwaitValue())
+        assertEquals(View.GONE, viewModel.getErrorButtonVisibility().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onResume should fetch stores and show progress`() = runTest {
+        // Given
+        val stores = listOf(
+            Store(1, "店舗1"),
+            Store(2, "店舗2")
+        )
+        whenever(mockApi.fetchStores()).thenReturn(stores)
+        
+        // When
+        viewModel.onResume()
+        
+        // Then
+        verify(mockApi).fetchStores()
+        assertEquals(stores, viewModel.getData().getOrAwaitValue())
+        assertEquals(View.GONE, viewModel.getProgressVisibility().getOrAwaitValue())
+        assertEquals(View.VISIBLE, viewModel.getRecyclerViewVisibility().getOrAwaitValue())
+        assertEquals(View.GONE, viewModel.getErrorButtonVisibility().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `fetchStores with empty result should show error button`() = runTest {
+        // Given
+        whenever(mockApi.fetchStores()).thenReturn(emptyList())
+        
+        // When
+        viewModel.onResume()
+        
+        // Then
+        assertEquals(emptyList<Store>(), viewModel.getData().getOrAwaitValue())
+        assertEquals(View.GONE, viewModel.getProgressVisibility().getOrAwaitValue())
+        assertEquals(View.GONE, viewModel.getRecyclerViewVisibility().getOrAwaitValue())
+        assertEquals(View.VISIBLE, viewModel.getErrorButtonVisibility().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `fetchStores failure should show error dialog and button`() = runTest {
+        // Given
+        val exception = RuntimeException("Network error")
+        whenever(mockApi.fetchStores()).thenThrow(exception)
+        
+        // When
+        viewModel.onResume()
+        
+        // Then
+        verify(mockListener).onShouldShowErrorDialog("Network error")
+        assertEquals(View.GONE, viewModel.getProgressVisibility().getOrAwaitValue())
+        assertEquals(View.GONE, viewModel.getRecyclerViewVisibility().getOrAwaitValue())
+        assertEquals(View.VISIBLE, viewModel.getErrorButtonVisibility().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onSelect should update global config and dismiss`() {
+        // Given
+        val store = Store(3, "選択店舗")
+        assertNull(fakeGlobalConfig.currentStore)
+        
+        // When
+        viewModel.onSelect(store)
+        
+        // Then
+        assertEquals(store, fakeGlobalConfig.currentStore)
+        verify(mockListener).onDismiss()
+    }
+    
+    @Test
+    fun `onReload should refetch stores`() = runTest {
+        // Given
+        val stores = listOf(Store(1, "店舗1"))
+        whenever(mockApi.fetchStores()).thenReturn(stores)
+        
+        // When
+        viewModel.onReload(null)
+        
+        // Then
+        verify(mockApi).fetchStores()
+        assertEquals(stores, viewModel.getData().getOrAwaitValue())
+    }
+    
+    @Test
+    fun `onClose should dismiss dialog`() {
+        // When
+        viewModel.onClose(null)
+        
+        // Then
+        verify(mockListener).onDismiss()
+    }
+    
+    @Test
+    fun `multiple concurrent fetch requests should only execute one`() = runTest {
+        // Given
+        val stores = listOf(Store(1, "店舗1"))
+        whenever(mockApi.fetchStores()).thenReturn(stores)
+        
+        // When - Start multiple fetches rapidly
+        viewModel.onResume()
+        viewModel.onReload(null)
+        viewModel.onReload(null)
+        
+        // Then - Only one API call should be made
+        verify(mockApi, times(1)).fetchStores()
+    }
+    
+    @Test
+    fun `requesting state should show only progress`() = runTest {
+        // Given
+        val stores = listOf(Store(1, "店舗1"))
+        whenever(mockApi.fetchStores()).thenAnswer {
+            // Check visibility states during request
+            assertEquals(View.VISIBLE, viewModel.getProgressVisibility().value)
+            assertEquals(View.GONE, viewModel.getRecyclerViewVisibility().value)
+            assertEquals(View.GONE, viewModel.getErrorButtonVisibility().value)
+            stores
+        }
+        
+        // When
+        viewModel.onResume()
+        
+        // Then
+        verify(mockApi).fetchStores()
+    }
+}
\ No newline at end of file
diff --git a/buildSrc/src/main/java/dependencies/Dep.kt b/buildSrc/src/main/java/dependencies/Dep.kt
index 7e92045..40da79e 100644
--- a/buildSrc/src/main/java/dependencies/Dep.kt
+++ b/buildSrc/src/main/java/dependencies/Dep.kt
@@ -3,7 +3,7 @@ package dependencies
 @Suppress("SpellCheckingInspection")
 object Dep {
     object Koin {
-        const val android = "io.insert-koin:koin-android:3.1.2"
+        const val android = "io.insert-koin:koin-android:3.5.0"
     }
 
     object Zxing {
diff --git a/buildSrc/src/main/java/dependencies/Versions.kt b/buildSrc/src/main/java/dependencies/Versions.kt
index 21350d3..397f393 100644
--- a/buildSrc/src/main/java/dependencies/Versions.kt
+++ b/buildSrc/src/main/java/dependencies/Versions.kt
@@ -1,9 +1,9 @@
 package dependencies
 
 object Versions {
-    const val compileSdk = 33
+    const val compileSdk = 35
     const val minSdk     = 23
-    const val targetSdk  = 33
+    const val targetSdk  = 35
 
     const val versionCode = 8
     const val versionName = "1.0.7"
diff --git a/check_newlines.sh b/check_newlines.sh
new file mode 100755
index 0000000..a07a94f
--- /dev/null
+++ b/check_newlines.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+# Find all Kotlin, Java, XML, and Gradle files
+find . -type f \( -name "*.kt" -o -name "*.java" -o -name "*.xml" -o -name "*.gradle" -o -name "*.gradle.kts" \) -not -path "./build/*" -not -path "./.gradle/*" -not -path "./app/build/*" -not -path "*/build/*" | while read -r file; do
+    # Check if file exists and is readable
+    if [ -r "$file" ]; then
+        # Check if the last character is a newline
+        if [ -s "$file" ] && [ "$(tail -c 1 "$file" | wc -l)" -eq 0 ]; then
+            echo "$file"
+        fi
+    fi
+done
\ No newline at end of file
diff --git a/docs/TESTING.md b/docs/TESTING.md
new file mode 100644
index 0000000..4f62f6a
--- /dev/null
+++ b/docs/TESTING.md
@@ -0,0 +1,146 @@
+# Testing Documentation
+
+This document describes the comprehensive testing infrastructure implemented for the Kids POS Android project.
+
+## Test Structure
+
+### Unit Tests (`app/src/test/`)
+
+Unit tests are located in the `test` source set and test individual components in isolation.
+
+#### ViewModels
+- `MainViewModelTest` - Tests for the main activity view model
+- `ItemListViewModelTest` - Tests for item list functionality
+- `CalculatorDialogViewModelTest` - Tests for calculator/payment logic
+- `StoreListViewModelTest` - Tests for store selection
+
+#### API
+- `APIServiceTest` - Tests API service with MockWebServer
+
+#### Test Utilities
+- `CoroutineTestRule` - JUnit rule for coroutine testing
+- `FakeEventBus` - Fake implementation of EventBus for testing
+- `FakeGlobalConfig` - Fake configuration for testing
+- `LiveDataTestUtil` - Extension functions for testing LiveData
+
+### Instrumented Tests (`app/src/androidTest/`)
+
+UI tests using Espresso that run on an Android device or emulator.
+
+- `MainActivityTest` - Tests main activity UI interactions
+- `ItemListFragmentTest` - Tests item list fragment
+- `LaunchActivityTest` - Tests launch screen functionality
+- `EspressoTestUtil` - Helper functions for UI tests
+
+## Running Tests
+
+### Unit Tests
+```bash
+# Run all unit tests
+./gradlew test
+
+# Run tests for specific variant
+./gradlew testProdDebugUnitTest
+./gradlew testDemoDebugUnitTest
+
+# Run with coverage
+./gradlew jacocoTestReport
+```
+
+### Instrumented Tests
+```bash
+# Run on connected device/emulator
+./gradlew connectedAndroidTest
+
+# Run for specific variant
+./gradlew connectedProdDebugAndroidTest
+```
+
+### Code Coverage
+```bash
+# Generate coverage report
+./gradlew jacocoTestReport
+
+# Check coverage thresholds
+./gradlew jacocoTestCoverageVerification
+```
+
+Coverage reports are generated at:
+- HTML: `app/build/reports/jacoco/jacocoTestReport/html/index.html`
+- XML: `app/build/reports/jacoco/jacocoTestReport/jacocoTestReport.xml`
+
+## Coverage Requirements
+
+- Overall coverage: 70%
+- Per-class line coverage: 60% (excluding entities, DI, and generated code)
+
+## CI/CD Integration
+
+### GitHub Actions Workflows
+
+1. **Android CI** (`android-ci.yml`)
+   - Runs on push to main/develop/feat-* branches
+   - Executes lint checks, unit tests, and builds APKs
+   - Runs instrumented tests on multiple API levels (26, 29, 33)
+   - Uploads test results and coverage to Codecov
+
+2. **PR Checks** (`pr-checks.yml`)
+   - Runs on pull requests
+   - Performs code quality checks (Detekt, ktlint)
+   - Checks APK size constraints
+   - Runs Danger for automated PR review
+
+3. **Dependency Updates** (`dependabot.yml`)
+   - Weekly automated dependency updates
+   - Separate configurations for Gradle and GitHub Actions
+
+## Best Practices
+
+1. **Test Naming**: Use descriptive names with backticks for readability
+   ```kotlin
+   @Test
+   fun `should return error when network fails`() { }
+   ```
+
+2. **Test Structure**: Follow AAA pattern
+   ```kotlin
+   @Test
+   fun testExample() {
+       // Arrange (Given)
+       val input = "test"
+       
+       // Act (When)
+       val result = someFunction(input)
+       
+       // Assert (Then)
+       assertEquals("expected", result)
+   }
+   ```
+
+3. **Coroutine Testing**: Use `runTest` for suspend functions
+   ```kotlin
+   @Test
+   fun `test coroutine function`() = runTest {
+       // Test implementation
+   }
+   ```
+
+4. **LiveData Testing**: Use `getOrAwaitValue()` extension
+   ```kotlin
+   val result = viewModel.someData.getOrAwaitValue()
+   assertEquals(expected, result)
+   ```
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Flaky UI Tests**: Use `EspressoTestUtil.waitFor()` for timing issues
+2. **Coroutine Test Failures**: Ensure `CoroutineTestRule` is applied
+3. **MockWebServer Issues**: Check proper setup/teardown in @Before/@After
+
+### Debug Tips
+
+- Run tests with `--info` flag for detailed output
+- Use `@RunWith(AndroidJUnit4::class)` for instrumented tests
+- Check Logcat for detailed error messages during UI tests
\ No newline at end of file
diff --git a/gradle.properties b/gradle.properties
index 902438c..ff4444b 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,7 +1,6 @@
-org.gradle.jvmargs=-Xmx4096m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
+org.gradle.jvmargs=-Xmx4096m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
 org.gradle.parallel=true
 android.useAndroidX=true
-android.enableJetifier=true
-android.defaults.buildfeatures.buildconfig=true
-android.nonTransitiveRClass=false
+android.enableJetifier=false
+android.nonTransitiveRClass=true
 android.nonFinalResIds=false
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index ae5dc4f..ab8edac 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,33 +1,34 @@
 [versions]
-desugar_jdk_libs = "2.0.3"
-kotlin = "1.8.20"
-kotlinx-coroutines = "1.7.2"
-kotlinx-serialization = "1.6.0"
-dagger = "2.46.1"
+desugar_jdk_libs = "2.1.3"
+kotlin = "1.9.25"
+kotlinx-coroutines = "1.9.0"
+kotlinx-serialization = "1.6.3"
+dagger = "2.51.1"
 
-android-gradle-plugin = "8.1.1"
+android-gradle-plugin = "8.7.3"
 cookpad-lisence-plugin = "1.2.8"
 
-core-ktx = "1.10.1"
-activity-ktx = "1.7.2"
-fragment-ktx = "1.6.0"
-preference-ktx = "1.2.0"
-viewmodel-ktx = "2.6.1"
+core-ktx = "1.15.0"
+activity-ktx = "1.9.3"
+fragment-ktx = "1.8.5"
+preference-ktx = "1.2.1"
+viewmodel-ktx = "2.8.7"
 
-appcompat = "1.6.1"
-recyclerview = "1.3.0"
-material = "1.9.0"
+appcompat = "1.7.0"
+recyclerview = "1.3.2"
+material = "1.12.0"
 swiperefreshlayout = "1.1.0"
-browser = "1.5.0"
-exifinterface = "1.3.6"
+browser = "1.8.0"
+exifinterface = "1.3.7"
 installreferrer = "2.2"
 constraintlayout = "2.1.4"
 
-okhttp = "4.10.0"
-retrofit = "2.9.0"
+okhttp = "4.12.0"
+retrofit = "2.11.0"
 retrofit-kotlin-serialization-converter = "1.0.0"
-mockito = "5.0.0"
-robolectric = "4.10.3"
+mockito = "5.14.2"
+mockito-kotlin = "5.4.0"
+robolectric = "4.13"
 espresso = "3.5.1"
 
 [libraries]
@@ -40,7 +41,7 @@ androidx-viewmodel-ktx = { module = "androidx.lifecycle:lifecycle-viewmodel-ktx"
 androidx-appcompat = { module = "androidx.appcompat:appcompat", version.ref = "appcompat" }
 androidx-recyclerview = { module = "androidx.recyclerview:recyclerview", version.ref = "recyclerview" }
 androidx-constraintlayout = { module = "androidx.constraintlayout:constraintlayout", version.ref = "constraintlayout" }
-androidx-hilt-compiler = { module = "androidx.hilt:hilt-compiler", version = "1.0.0" }
+androidx-hilt-compiler = { module = "androidx.hilt:hilt-compiler", version = "1.2.0" }
 
 android-material = { module = "com.google.android.material:material", version.ref = "material" }
 desugar_jdk_libs = { module = "com.android.tools:desugar_jdk_libs", version.ref = "desugar_jdk_libs" }
@@ -52,7 +53,7 @@ kotlinx-serialization-json = { module = "org.jetbrains.kotlinx:kotlinx-serializa
 dagger-hilt-android = { module = "com.google.dagger:hilt-android", version.ref = "dagger" }
 dagger-hilt-android-compiler = { module = "com.google.dagger:hilt-android-compiler", version.ref = "dagger" }
 
-firebase-bom = { module = "com.google.firebase:firebase-bom", version = "32.2.3" }
+firebase-bom = { module = "com.google.firebase:firebase-bom", version = "33.7.0" }
 firebase-analytics-ktx = { module = "com.google.firebase:firebase-analytics-ktx" }
 firebase-crashlytics-ktx = { module = "com.google.firebase:firebase-crashlytics-ktx" }
 
@@ -64,7 +65,6 @@ retrofit-client = { module = "com.squareup.retrofit2:retrofit", version.ref = "r
 retrofit-converter-serialization = { module = "com.jakewharton.retrofit:retrofit2-kotlinx-serialization-converter", version.ref = "retrofit-kotlin-serialization-converter" }
 
 logger = { module = "com.orhanobut:logger", version = "2.2.0" }
-stetho = { module = "com.facebook.stetho:stetho-okhttp3", version = "1.6.0" }
 eventbus = { module = "org.greenrobot:eventbus", version = "3.2.0" }
 
 #Test
@@ -82,7 +82,7 @@ test-okhttp-mockwebserver = { module = "com.squareup.okhttp3:mockwebserver" }
 
 test-mockito-inline = { module = "org.mockito:mockito-inline", version.ref = "mockito" }
 test-mockito-android = { module = "org.mockito:mockito-android", version.ref = "mockito" }
-test-mockito-kotlin = { module = "org.mockito.kotlin:mockito-kotlin", version.ref = "mockito" }
+test-mockito-kotlin = { module = "org.mockito.kotlin:mockito-kotlin", version.ref = "mockito-kotlin" }
 
 test-robolectric-client = { module = "org.robolectric:robolectric", version.ref = "robolectric" }
 
@@ -97,9 +97,9 @@ android-application = { id = "com.android.application", version.ref = "android-g
 android-library = { id = "com.android.library", version.ref = "android-gradle-plugin" }
 
 kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
-kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlinx-serialization" }
+kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }
 
-google-services = { id = "com.google.gms.google-services", version = "4.3.10" }
-firebase-crashlytics = { id = "com.google.firebase.crashlytics", version = "2.8.1" }
+google-services = { id = "com.google.gms.google-services", version = "4.4.2" }
+firebase-crashlytics = { id = "com.google.firebase.crashlytics", version = "3.0.2" }
 
 dagger-hilt = { id = "com.google.dagger.hilt.android", version.ref = "dagger" }
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 485b6ca..02ca2c3 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 #Wed Apr 20 15:46:52 JST 2022
 distributionBase=GRADLE_USER_HOME
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.9-bin.zip
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME