My Sex Slave is a Classmate

User Summary The father of Masato Kirishima was the CEO of Kirishima Conglomerate and he died a week ago. Masato have been chosen to take over the mighty family company but according to the family tradition he have to pick a girl who willingly agrees to be his sex slave. One possible girl is presented to him: The sister of his father's secretary who is also one of his classmates. He have three weeks to train her.