English follows:

小学校から帰ってきた長男が、ちょっとうれしそうな顔で話しかけてきた。

「跳び箱の上ででんぐりがえりする地獄みたいなやつあんじゃん？　今日あれ、できたよ」

Taka came back from primary school and talked to me with a joyful face.

“Don’t you know the hell-like gymnastics technique that you do forward roll on a jumping box, do you? I did it today!”

What the hell? Congratulations my boy!