Rapid Express Train Bound for Otokogai.

A boy who is trying to win on the train. Even though he's in the car, he exposes himself. However, it was a nuisance for the two men who had made that area their territory. They immediately catch the boy and question him about why he is here, but...As the story progresses, the journey of "self-discovery" of a boy and two men becomes clearer, and eventually the gap between utopia and reality stands in front of the three.