While Shizuka is at home engaging in a sexual encounter with her lover, Yukio, her daughter Yuka returns home after finishing her final exams and witnesses the scene. Devastated, Yuka flees the house. Afterward, Yukio suggests that Shizuka introduce him to her family, but she remains hesitant. Driven to despair, Yuka is approached by a university student named Tatsuhiko, who takes her to his apartment and sleeps with her. Upon hearing about Yuka’s suspicions regarding her mother, Tatsuhiko convinces her to join him in a scheme to extort money from Shizuka...
