For a while now Shina been a stranger in his own home. His dad is almost never home, his mom ignores him most of the time, and his little brother hates him. This leads to Shina falling into a depression and sleeping with an older married woman for money. Sasakawa, Shina's math teacher, has been in love with Shina for some time but he was content to keep Shina at a distant until he finds out about Shina's affair.
- Bastard Boyfriend: Sasakawa is supposed to be in love with Shina but doesn't hesitate to rape him and readily admits that he's been sleeping with someone else while going out with him.
- Lolicon: It's hinted that Sasakawa is one since he is also dating a female junior high student, and he admits that he's not attracted to normal women.
- Oedipus Complex: Discussed as the reason why Shina sleeps with a woman who's old enough to be his mom.
- Parental Substitute: For a while Shina's homeroom teacher and his wife serve as his parental substitute.