Near the beginning of the movie the twins Seizo (Keigo Matsuyama, 8) and Yukihiko (Shogo Matsuyama, 8) are seen fighting each other in the nude. Their sister Ikuko (Mizuki Mamata, 14?) teases them, but it backfires on her.

Later several boys (8-10), including the twins, are seen skinny dipping. When they notice that their classmate Hatsumi (Mika Yamauchi, 8?) is watching them, they feel embarrassed for being seen naked by her.

Later one of the twins removes his clothes to swim after his hat which has blown into the water. He is saved by his brother.

One of the twins attempts to touch his sister's breast.

Seizo takes a bath with his mother, who shows him her private parts to explain to him that boys and girls are different.