Kojima is a female chess player with a bit of reputation for her passion for challenging other masters. Once she received a challenging letter full of provocation from an unknown person, the reward for winning would be a large sum of money, but if she lost, she had to agree to do what he requested. Of course, she agreed. The final confrontation day arrived, after a fierce battle, Kojima finally accepted defeat due to her own arrogance and conceit. The other person's condition was not too difficult to fulfill, just that she had to be obedient and serve him naked, helping him satisfy his sexual needs.