Saki, a 32-year-old married woman who works as a swimming instructor at a sports club in Tokyo, watches the male members swimming from the poolside. One man, Yoshino, is ogling her with erotic eyes. He is a swimsuit fanatic who travels from one swimming class to another, targeting female competitive swimmers as his prey. Having set his sights on Saki, Yoshino purposely scams the car Saki is driving, blackmailing her by creating an accident resulting in a fatality. Saki is then forced to wear revealing swimsuits with perverted designs for every class... "Oh, even in the eyes of a maniac like me, you have the best body," says the married woman as she is gang-raped by the male members of the sports club.