QuantEcon · mmcky · Jun 9, 2026 · Jun 25, 2026
diff --git a/dist-action/glossary/ja.json b/dist-action/glossary/ja.json
diff --git a/dist-action/index.js b/dist-action/index.js
@@ -23908,15 +23908,16 @@ var LANGUAGE_CONFIGS = {
       "Keep technical terms and code examples in English/Latin script",
       "Use formal/academic Persian style appropriate for educational content"
     ]
+  },
+  "ja": {
+    code: "ja",
+    name: "Japanese",
+    additionalRules: [
+      "Use proper full-width Japanese punctuation marks (\u3001\u3002\u300C\u300D) not ASCII punctuation (,.) in prose text",
+      "Always insert a space between Japanese characters and inline MyST directives ({doc}, {ref}, {any}, {term}, etc.) or Markdown links ([text](url))"
+    ]
   }
   // Future language configurations can be added here:
-  // 'ja': {
-  //   code: 'ja',
-  //   name: 'Japanese',
-  //   additionalRules: [
-  //     'Use proper Japanese punctuation marks (、。「」)',
-  //   ],
-  // },
   // 'es': {
   //   code: 'es',
   //   name: 'Spanish',

diff --git a/dist-action/index.js.map b/dist-action/index.js.map
diff --git a/docs/user/glossary.md b/docs/user/glossary.md
@@ -12,8 +12,11 @@ The glossary system ensures consistent translation of technical terminology acro
 |----------|------|-------|--------------|
 | Chinese (Simplified) | `glossary/zh-cn.json` | 357 | October 2025 |
 | Farsi | `glossary/fa.json` | 357 | December 2025 |
+| Japanese | `glossary/ja.json` | 357 | June 2026 (draft) |
 
-Both glossaries are bundled with the action and loaded automatically when the `target-language` matches. No configuration needed.
+These glossaries are bundled with the action and loaded automatically when the `target-language` matches. No configuration needed.
+
+> The Japanese glossary is an initial draft pending native-speaker review.
 
 ## How it works
 

diff --git a/docs/user/language-config.md b/docs/user/language-config.md
@@ -12,7 +12,7 @@ Each target language can have specific translation rules that are automatically
 |------|----------|--------|
 | `zh-cn` | Chinese (Simplified) | ✅ Configured |
 | `fa` | Farsi (Persian) | ✅ Configured |
-| `ja` | Japanese | Planned |
+| `ja` | Japanese | ✅ Configured (draft glossary) |
 | `es` | Spanish | Planned |
 
 ## Current rules
@@ -27,6 +27,11 @@ Each target language can have specific translation rules that are automatically
 - Keep technical terms and code examples in English/Latin script
 - Use formal/academic Persian style appropriate for educational content
 
+### Japanese — `ja`
+
+- Use proper full-width Japanese punctuation marks (、。「」) not ASCII punctuation (,.) in prose text
+- Insert a space between Japanese characters and inline MyST directives or Markdown links
+
 ## How rules are applied
 
 Language rules are appended to every translation prompt as numbered rules after the standard instructions. For example, when translating to `zh-cn`, Claude's prompt includes:

diff --git a/glossary/README.md b/glossary/README.md
@@ -10,17 +10,21 @@ Each language has its own glossary file:
 glossary/
 ├── README.md          # This file
 ├── zh-cn.json         # Simplified Chinese glossary
-├── ja.json            # Japanese glossary (future)
-└── es.json            # Spanish glossary (future)
+├── fa.json            # Persian/Farsi glossary
+└── ja.json            # Japanese glossary
 ```
 
+Planned languages (`es`, `zh-tw`, `fr`) are listed under
+[File Naming Convention](#file-naming-convention) below.
+
 ## File Naming Convention
 
 Glossary files are named using **language codes**:
 
 - `zh-cn.json` - Simplified Chinese (中文简体)
+- `fa.json` - Persian/Farsi (فارسی)
+- `ja.json` - Japanese (日本語)
 - `zh-tw.json` - Traditional Chinese (中文繁體) - future
-- `ja.json` - Japanese (日本語) - future
 - `es.json` - Spanish (Español) - future
 - `fr.json` - French (Français) - future
 
@@ -68,9 +72,21 @@ When the action runs with `target-language: 'zh-cn'`:
 
 ### Japanese (`ja.json`)
 
-**Status**: 🚧 Planned
+**Status**: 🟡 Draft (357 terms) — pending native-speaker review
 
-Will include translations for all terms in the existing glossaries.
+**Contents**:
+- ~160 economic terms (国内総生産, 均衡, 財政政策, etc.)
+- ~100 mathematical terms (固有値, 行列, 微分, etc.)
+- ~35 statistical terms (分布, 回帰, 分散, etc.)
+- ~45 economist names (ロバート・ソロー, ケネス・アロー, etc.)
+- ~17 miscellaneous terms
+
+**Notes**: Mirrors the English term set of the `zh-cn` / `fa` glossaries.
+Abbreviations expand to the full Japanese term with the abbreviation in
+parentheses (e.g. GDP → 国内総生産（GDP）). Personal names are transliterated
+to katakana; CJK-origin researcher names (e.g. Hiroki Kondo, Yoshi Fujiwara,
+and the Chinese-origin names) should be reviewed by the authors so preferred
+kanji can replace the katakana placeholders before promoting to ✅ Complete.
 
 ### Spanish (`es.json`)
 
@@ -239,4 +255,4 @@ These glossaries are part of the Translation Sync Action and inherit its license
 ---
 
 **Maintained by**: QuantEcon Team  
-**Last updated**: December 5, 2025
+**Last updated**: June 9, 2026