Mario, a boy whose father works at a game company, is asked to become a GM. Although reluctant, he analyzes the game and realizes that he can experience the stimuli received in the game in real life, and as an experiment, he targets Koharu Takashina, a quiet girl. Koharu wishes to become a "helpful and glamorous character" that is the opposite of her real self. However, the class she is given is a prostitute! She is violated by rough men, and even though she is still a virgin in real life, her womb throbs――.