diff --git a/API/I18N/ja.json b/API/I18N/ja.json
index 0967ef424..384986fcf 100644
--- a/API/I18N/ja.json
+++ b/API/I18N/ja.json
@@ -1 +1,3 @@
-{}
+{
+    "chapter-num": "章 {0}"
+}