Koudai, a lustful father-in-law, constantly makes physical advances toward his son's wife, Ryoko, driven by a growing, lewd desire to sleep with her. One day, taking advantage of Ryoko's injury that leaves her immobile, Koudai forcibly touches her body under the pretense of "treatment," then seizes the moment to overpower her completely. Before she can even scream for help, Ryoko is violently raped. From that day on, Koudai's humiliating torment of his daughter-in-law begins, completely shattering her life.