Her parents died early, so Asuka Momose is living with her older brother. He was a delinquent and owed a large amount of money. One day the creditor came to claim him after begging many times. This time, he saw the beautiful Asuka coming out of the room, so he wanted to exchange that debt for having sex with the debtor's sister. Feeling sorry for him, she agreed. The next day the creditor brought a rope and tied Asuka up. He would definitely have sadistic sex with her.