Ichika had long fallen in love with her brother. She often had intimate acts with onii-chan that made him unable to help but dream of being able to massage those beautiful buttocks. One day, Ichika was confessed by a handsome, kind tenor friend in class. But because she was in love with onii-chan, she couldn't accept his confession. Because she avoided being embarrassed when she met every time, she didn't know how to answer him. He didn't give up, but wanted Ichika to answer. Ichika decides to tell him that she fell in love with onii-chan so that he would give up hope. Knowing Ichika's weakness, he wanted her to satisfy him. Ichika's Onii-chan also witnessed this, and when he got home, seeing those beautiful buttocks again made him unforgivable and unforgivable...