When his father disappears and he is in debt, Haru decides to work as a live-in at an inn to earn money for his mother's medical expenses. - One day, a demon appears and steals a customer's wallet. - A senior maid who is in love with Haru sees this and blames her for doing it. - The senior maid is subjected to lewd sex by the inn's proprietress as punishment, and uses that as an excuse to press Chiharu into having a physical relationship with her. - Chiharu complies out of guilt. - The demands of the senior maid escalate day by day.