Minamo Nagase used her skills and charm to seduce Daisuke, her sister Arisu's boyfriend. One night, while Daisuke was sleeping in bed with Arisu, Minamo snuck in to tempt him. Daisuke could not contain the appeal of Minamo's big breasts and skillful techniques, so he was tempted by Minamo again and again. And then Arisu also found out and had a "duel" with Minamo to find out who makes Daisuke feel better!!!