diff --git a/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java b/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
index e0e854c..ed57da3 100644
--- a/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
+++ b/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
@@ -154,6 +154,7 @@
      * @param month 月
      * @param day 日
      * @param title 追加するべきtodoのタイトル
+     * @return 新しいtodoのid
      */
     public int addTodo(String accountId, int bookId, int year, int month, int day, String title){
         if(!todos.containsKey(accountId)){
@@ -189,6 +190,7 @@
      * @param bookId 本のid
      * @param yearMonthDay 年月日を-で区切った文字列(yyyy-mm-dd)
      * @param title 追加したいtodoのタイトル
+     * @return 新しいtodoのid
      */
     public int addTodo(String accountId, int bookId, String yearMonthDay, String title){
         String[] yearMonthDays = yearMonthDay.split("-");