Based on a game by Guilty+.

Urara starts working at a girls' school. She is now happy because she will get married in a few months. But one day, her fiance suddenly goes missing since his business didn't go well. Months later, Yuji, a debt collector, comes to her house, but she doesn't have enough money to pay. Yuji offers her to work at a boys' school his friend works. He also says if she works there for a month, she won't need to pay back money. She finally decides to accept his offer without knowing the fact that the school is full of evil teachers and students....