The Secret Relationship between Brother and Sister-in-lawYumi leads a calm married life with her husband. One day, her husband's younger brother, Ryosuke, decides to stay with her until he takes his exams. However, Ryosuke became frustrated with the nightly activities of Yumi and her brother that he hears oh so well. One day, Ryosuke's desire explodes and he attacks Yumi, but she accepts it with open arms...