The Sakuma siblings are the daughter and son of a famous company in a certain prefecture in the Kanto region. The elder sister, Emi, a female college student, lives in an apartment in Tokyo that her father bought, and her younger brother, Yuji, is staying there while studying for his entrance exams. One day, a man calling himself Kudo visits her and tells her that her father's company has gone bankrupt, and seizes ownership of the apartment. He then sets his sights on Emi's beauty and makes his body his victim, using it to pay off the debt! Day after day, he and his henchmen pin Emi down, and even make his virgin younger brother have sex with Emi in a show of immorality...