Sayaka's family is rich, but her parents suddenly go missing. She gets a part-time job at the family restaurant. But Kuroki, the restaurant's boss, says that her family is missing due to large debts, and to pay off her parents' debt Kuroki gives her an idea: "Our restaurant offers special services at midnight only. If you put your name on the menu, you can pay off the debt faster." Sayaki decides to work at night to pay off her parents' debts...