diff --git a/docs/index.en.md b/docs/index.en.md
index c81e027..646e1b5 100644
--- a/docs/index.en.md
+++ b/docs/index.en.md
@@ -55,3 +55,5 @@ The total prize money is over 1 million yen. For details, please refer to the [2
 ![TOM'S Racing Kart](./assets/racing-kart.jpeg)
 
 ## Challenges
+
+The racing kart will drive around a circuit course and compete for the time it takes to complete a set number of laps. Although the cars will be driving alone this time, in the future they will be driving together with others. Therefore, there is a challenge to avoid virtual objects placed on the course.
diff --git a/docs/index.ja.md b/docs/index.ja.md
index 5c36b79..eb882b2 100644
--- a/docs/index.ja.md
+++ b/docs/index.ja.md
@@ -56,3 +56,5 @@
 ![TOM'S Racing Kart](./assets/racing-kart.jpeg)
 
 ## 挑戦課題
+
+サーキットコースを走行し、規定の周回数に到達するまでの走行時間を競います。また、今回は単独での走行になりますが、将来的には他の車両と同時に走ることを想定し、コース上に設置された仮想的な障害物の回避にも挑戦していただきます。