The training camp for the Hadogumi has begun. However, on the morning of the second day, Susumu collapses. Surprisingly, Susumu can't sleep unless he listens to his mother's lullaby, and he couldn't sleep at all last night. Susumu is embarrassed when his friends find out his secret. And, as expected, even Matenro found out about the secret. Matenro declares to Susumu that he will steal her lullaby.