Kojima is a female chess player with a bit of fame and a passion for challenging other masters. One day she received a letter of challenge filled with defiance from an anonymous opponent, with a large sum of money as a reward for victory, but if she lost, she would have to agree to follow whatever he demanded. Of course, she accepted. The day of the final confrontation arrived, and after an intense battle, Kojima ultimately conceded defeat due to her overconfidence and arrogance. The conditions he set were not too difficult to fulfill; she just needed to be naked and obediently serve him to satisfy his sexual desires.