Mirei lived a modest life on her husband's small salary. One day, Mirei was encouraged to bet on horse racing by her neighbor, Kita, and she got on. Kita's predictions came true, and Mirei trusted him completely, so she became obsessed with horse racing that she even borrowed money from Kita. However, Kita had never bought a bet, and had made up a fictitious debt to the ignorant Mirei. He gathered his male friends and demanded Mirei's body as collateral for the debt. Even as she was being violated, Mirei soon began to feel a masochistic pleasure...