Kurou is a good-looking guy. Many women approach him, and he enjoys it. But he gets sick of it, and starts to live stoically. Since then, his real older sister, Riho, starts to approach him, and they finally sleep together... That's no good. They make love every night. But their parents find it, and he is kicked out of their house. On his first day at his new apartment, when he wakes up, he finds Riho giving him a blowjob...