Rika, a wife whose husband has been transferred away from home, lives in a single-parent household. One day, she finds out that her son Takashi is being bullied, and visits the home of Hashimoto, the ringleader. She thought that Hashimoto, who has been with Takashi since kindergarten, would understand if she talked to him, but he demands her body in exchange for stopping the bullying. "If that will help Takashi..." Rika says, and obediently offers her body. However, it won't end with a one-time thing, and one day Hashimoto comes to the house with his friends...