Secretly in love, the seductive younger sister entices her older brother for sex

Ichika has long been in love with her older brother. She often has intimate actions with her onii-chan that make him unable to resist dreaming about being able to touch those beautiful buttocks. One day, Ichika was confessed to by a tall, handsome, kind boy in class. But because she loves her onii-chan, she cannot accept his confession. To avoid feeling embarrassed every time they meet, she doesn't know how to respond to him.

He doesn't give up and wants Ichika to give him an answer. Ichika decides to tell him that she loves her onii-chan to make him give up hope. Knowing Ichika's weakness, he wants her to satisfy him. Ichika's onii-chan witnesses this and when he comes home, seeing those beautiful buttocks again makes him unable to control himself and do something unforgivable...