diff --git a/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java b/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
index a60d082..ed57da3 100644
--- a/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
+++ b/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
@@ -25,11 +25,6 @@
      */
     private final HashMap<String, Integer> nextTodoId = new HashMap<>();
 
-//    private final BookManager bookManager;
-//
-//    TodoManger(BookManager bookManager){
-//        this.bookManager = bookManager;
-//    }
 
     /**
      *
@@ -159,6 +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)){
@@ -181,11 +177,11 @@
             nextTodoId.put(accountBook, 0);
         }
 
-        int todoId = nextTodoId.get(accountBook);
-        Todo newTodo = new Todo(title, false, year, month, day, todoId);
-        todos.get(accountId).get(bookId).get(year).get(month).get(day).put(todoId, newTodo);
-        nextTodoId.put(accountBook, todoId + 1);
-        return todoId;
+        int newTodoId = nextTodoId.get(accountBook);
+        Todo newTodo = new Todo(title, false, year, month, day, newTodoId);
+        todos.get(accountId).get(bookId).get(year).get(month).get(day).put(newTodoId, newTodo);
+        nextTodoId.put(accountBook, newTodoId + 1);
+        return newTodoId;
     }
 
     /**
@@ -194,6 +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("-");