Kenji and his coworkers regularly hang out every night at their colleague Hiroshi's house for drinks. One day, a drunken Kenji sneaks into Hiroshi's sister Michi's room and catches sight of her while she's bathing. Mesmerized by her large, jiggling breasts and sexy figure, he becomes aroused and can't help but want to have sex with her. While Hiroshi is away, Kenji makes his move on Michi. She acts completely submissive, offering no resistance at all. Kenji indulges himself freely with the sensitive, lustful Michi to his heart's content.