Momoi Osamu

Inuhiko has blackmailed a female student, Kagido, with some embarrassing pictures, making her his sex slave. Kenji, a friend of Inuhiko, also wants a sex slave who happens to be a distant cousin of Kenji's. Together they use the girls whenever they want whether the girls want it or not.

In a lonely home without parents of any sort resides Keisuke surrounded by ten step sisters, all of which have the urge to get more intimate with their cute younger brother and they eventually suceed when Keisuke begins to realize their submissiveness.