Kyoko became Shingo's sister due to their parents' remarriage. She has to live with Shingo alone while their parents are on an overseas trip. Though she hides her sex drive in front of her brother, Kyoko is a horny idiot who desperately wants to get pregnant. Kyoko, who lives with Shingo, develops a desire for him and makes him drink an aphrodisiac to plan sexual intercourse. Furthermore, she also makes Shingo's friend drink the aphrodisiac and seduces both of them...
