姉ハメっ！

Takuma is a uni student, lazing around at home every day since his parents are abroad and his older sister lives separate from him. One day, he faces the danger of flunk. To make matters worse, his parents know it, and decide to arrange him a home tutor, Reika. At first, he studies hard, but loses motivation soon. Instead, he has another desire... which is to insult her. He studies hard since then, and makes a promise with her. She says, "If you solve all the questions I give, I'll follow any order you make." He finally makes it, and asks for her body...