夫と落ち着いた結婚生活を送るゆみ。ある日、夫の弟・りょうすけが受験まで居候することになった。しかし、りょうすけにとっては毎晩聞こえてくるゆみと兄の夜の営みに欲求不満を覚えていった。ある日、欲求が爆発してしまったりょうすけはゆみを襲ってしまうが、ゆみもそれを受け入れてしまうのであった…。Yumi 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…
