diff --git a/curriculum/challenges/japanese/10-coding-interview-prep/data-structures/check-if-binary-search-tree.md b/curriculum/challenges/japanese/10-coding-interview-prep/data-structures/check-if-binary-search-tree.md
index d22256746f..0b16b83746 100644
--- a/curriculum/challenges/japanese/10-coding-interview-prep/data-structures/check-if-binary-search-tree.md
+++ b/curriculum/challenges/japanese/10-coding-interview-prep/data-structures/check-if-binary-search-tree.md
@@ -39,7 +39,7 @@ assert(
 );
 ```
 
-`isBinarySearchTree()` should return false when checked with a tree that is not a binary search tree.
+`isBinarySearchTree()` は、二分探索木でない木を調べたときに false を返す必要があります。
 
 ```js
 assert(