Surprisingly enough, a series about the bombing of Hiroshima and its aftermath manages to have quite a bit of humorous scenes in it.

* Nearly half the things Ryuta says, especially in the manga.
* In a later volume of the manga, Ryuta and another boy escape from prison and need disguises. They pull a GoneSwimmingClothesStolen on a boy and girl they meet on the road to Hiroshima. The other escaped prisoner can only fit into the boy's clothes. Guess who's stuck wearing a frilly dress and a hat with bows?