One day, Kiyomi is caught by Taichi, her stepson's mischievous friend, masturbating with a hidden vibrator. Before she can react in embarrassment, she's suddenly attacked. Her soft, drooping big tits—stretching up to one meter—are roughly kneaded, while her pink pussy meat is gently bitten and teased, gradually clouding her senses. A thick cock is forced into her tight little slit, and despite her massive breasts trembling, she is soon driven to climax. The sexual desire awakened by being taken by the young man won't subside, and she eventually turns her attention to her stepson, who has feelings for her. This impulsive act marks the beginning of a new, forbidden relationship.