Kokoro is a beautiful girl from a single-mother household. One day, her mother Meari, who works at a snack bar, brings home a stepfather named Kita. Kita forces Kokoro to watch him have sex with Meari to arouse her, and then he makes her his own. He slowly caresses her to instill pleasure before deflowering her... But it doesn't end there; Kita uses Kokoro as collateral for his debts, letting debt collectors rape her. After being continuously violated by these vulgar men, Kokoro eventually awakens to her masochistic tendencies...