Tsukasa had a mission that involved killing a villain named Rui. it was written in books that he was crazy and did not show any kind of softness to anyone. but when knight finally met him, he found out that Rui wasn't like everyone said. he was a lonely, cheerful man who only wanted love which he could not achieve

Tsukasa's soft heart wouldn't let him leave Rui alone again, so he brought him to his kingdom and showed everyone that Rui wasn't like that. women started having a crush on him.