Hoshino is a plain office lady with glasses and long bangs. One day while working overtime, she gets into a physical relationship with a playboy colleague she has a crush on. Hoshino is extremely shy even about showing her naked body, but after having sex with him once, she changes completely! Using techniques she learned from the erotic manga she was always reading, she attacks her colleague and makes him weak to the bone. The relationship between the two, who have switched roles, continues to play out in the office.