Yuu, a NEET and social outcast, spends his days holed up at home, immersed in erotic games. Eager to test out the erotic techniques he's honed in those games, Yuu decides to experiment with his sassy younger sister. They agree to a game where the loser has to obey whatever the winner says, and the stakes are raised with a promise of humiliation. After a decisive victory, Yuu forces his busty sister to wear revealing lingerie...
