Three years into her marriage, housewife Shiho struggles with a sexless relationship and growing dissatisfaction in her daily life. One day, while riding the train, she accidentally becomes the victim of molestation—but instead of fear, she discovers an unexpected thrill. From that moment on, Shiho's thoughts become consumed by the experience, transforming her routine into an eager anticipation for the next encounter. With her relationship with her husband remaining cold and distant, Shiho finds herself increasingly unable to resist the desire for further molestation.