As the older brother speaks to the camera, his younger sister, who moved to Tokyo years ago, returns home for the first time in a while. Since childhood, the brother has harbored romantic feelings for his sister. With her short hair and boyish charm, she has always stirred emotions within him. Eager to reconnect during her visit, the brother secretly desires to watch his sister masturbate. She agrees to let him witness up close as she slips her hand into her panties, captivating him completely. Late at night, when she suddenly approaches him seductively, asking, "Onii-chan, aren't you going to put it in...?" he is shocked by his own instant, full erection.