diff --git a/src/main/java/org/ntlab/citrusserver/repositories/FavoriteManager.java b/src/main/java/org/ntlab/citrusserver/repositories/FavoriteManager.java
index b7a9e18..fd8d085 100644
--- a/src/main/java/org/ntlab/citrusserver/repositories/FavoriteManager.java
+++ b/src/main/java/org/ntlab/citrusserver/repositories/FavoriteManager.java
@@ -129,10 +129,15 @@
     public void removeFavoriteByBookID(String accountId, Integer bookId) {  // accountIdはamika1107
         if(favoritedMap.containsKey(accountId) && favoritedMap.get(accountId).containsKey(bookId)) {
             for (String otherAccountId : favoritedMap.get(accountId).get(bookId)){
-                favoritesMap.get(otherAccountId).get(accountId).remove(bookId); // tesのbookId を削除
+                favoritesMap.get(otherAccountId).get(accountId).remove(bookId);
+                if(favoritesMap.get(otherAccountId).get(accountId).isEmpty()) {
+                    favoritesMap.get(otherAccountId).remove(accountId);
+                }// tesのbookId を削除
             }
             favoritedMap.get(accountId).remove(bookId);  // tedのbookIdを消したいとき
         }
+
+
     }
 
     @Override