My sister saw me masturbating to an erotic game about younger sisters. My sister, who is always straight-faced, then for some reason decided to help me masturbate... Will I be able to get a girlfriend when I can only get off on my sister? And why is my sister still watching me masturbate? This highly talked-about work, which won first place on FANZA, depicts the conflict of a brother who can only get off on his sister and his twisted relationship with his sister, and has been made into a live-action film with original sex scenes added under the supervision of the original author!