Twenty-four-year-old Chiyo Kozuka is down on her luck. Unemployed and with an empty bank account and three months behind her rent, she has no idea what to do. That is until her landlady knocks on her door and asks if they can have sex! If Chiyo agrees, the landlady promises to help her with financial issues.

The following day, Chiyo wakes up surprised to see her landlady sleeping next to her. Confused and hungover, she finds that she has no memory of the previous night. Nonetheless, when her landlady wakes up, she stays true to her word and proposes a unique financial agreement to Chiyo—one that Chiyo is in no position to deny!