Sara, a female teacher, has been secretly having an affair with her student, Hashimoto. She is so absorbed in the thrill of being with someone other than her husband that they often make love on school grounds. However, they are discovered by Ueda, a poor student in the class, and she is forced to give him her body in exchange... Of course, it doesn't end with just one encounter, and Ueda begins stalking her, using photographic evidence. Even her bad friend Hirai finds out about it, and she ends up calling Hashimoto to the classroom after school...