- Ai is serious, but she is not satisfied with her life with her husband, who has a special propensity, and secretly feels unsatisfied. At that time, his brother-in-law, Bunta, suddenly visits the house. - Her playful brother-in-law sees through her helplessness and skillfully persuades her. Swept away by his mouth, Ai ends up having a relationship "just once". - After that, she refuses Bunta, who relentlessly invites her, but the pleasure that shakes the whole body that can never be experienced by her husband, the stimulation that smashes the vaginal wall, is violently engraved on Ai's body.