Rui Kamishiro is the servant of the king Tsukasa Tenma himself. Rui was born in the dark kingdom, but never liked this place, that's why he ran away, without looking back. He doesn't know, what is like to be attached to country. He hides his past and tries not to think about it too much. He was too different, too kind, too strange to fit his homeland, and he was getting problems there. He doesn't like, how Tsukasa's parents manipulate their son, and always tries to remind him, that he's king. 