One day, Arisue and Chiaki, a married couple, encounter a mysterious woman who suddenly shows up at their door. The woman falls madly in love with Arisue at first sight and passionately demands to become his lover. However, Arisue rejects her by declaring, "My fetish is BDSM," and throws her a rope. As a result, the couple's training session turns extremely intense, leading to a brutal and spectacular development.