Yui and Mitsuki are sisters with different fathers. Their mother was burdened with debts from a rebel, and the three of them lived in poverty. One day, their mother announced that she was remarrying. Although elderly, she was wealthy and would take over the debt. Yui and Mitsuki were suspicious, but seeing their mother's smile for the first time in a while made them happy. And they began a dreamlike, wealthy life. However, without their mother's knowledge, the two were being raped every day by their stepfather, a man with a virile past. They chose to be raped, thinking that they could endure it if they were together...