Yui and Mitsuki are two sisters with the same father and different mother. Their mother is very poor, and the three still have to pay off the debt left by their father. One day, their mother said she would remarry. Even though she was a bit old, she could pay off all their debts. Although they were skeptical, when they saw their mother's happy smile that had been on for a long time, the two agreed. And then they lived the rich life they always dreamed of. But after a while, the two realized the true nature of their stepfather. Whenever his mother was not there, he repeatedly raped the two sisters and threatened to chase all three of them away if they dared to reveal this story...