I was fascinated by my girlfriend's sister's obscene luxury lingerie and her seductive kiss... I had sex with her over and over again, 17 times, hiding it from her. Mei Itsukaichi

The movie revolves around the boyfriend's fascination with his girlfriend's sister, Mei, and her luxurious lingerie. As they spend time together, they engage in intimate activities, hiding their actions from the girlfriend. The central dramatic tension arises from the secrecy and guilt associated with their affair, as they navigate their desires while trying to maintain the illusion of innocence.