diff --git a/client/strings/ja.json b/client/strings/ja.json
index 80af12d8..8d1f08c1 100644
--- a/client/strings/ja.json
+++ b/client/strings/ja.json
@@ -1,3 +1,5 @@
 {
-  "ButtonAdd": "追加"
+  "ButtonAdd": "追加",
+  "ButtonAddChapters": "チャプターの追加",
+  "ButtonCancel": "キャンセル"
 }