One day our hero, Ginji, comes across a bizarre sight: three beautiful girls fighting a harried battle while dressed in outrageous costumes. The are the lovely Jewel Knights Crusaders, defenders of justice: loyal Yuki, cheerful Ruri, and the hopelessly cute Hisui. When he's invited to join their crusade and test his street-fighting skills, he agrees, with one condition: he gets to do anything he wants to the girls. They concede, not knowing all the erotic games he has in store for them. Boy, are they in for a big surprise!