Kagari

Kagari is a handsome vampire who can turn into a black wolf. He is taken care of by his companion, Seto Ashiya, who gives him his blood to eat. He refused to live with humans because they die first, until he met Seto who promised that before he died, he would exorcise him. Kagari disapproves of Seto's plan to give his body to his little sister, but doesn't object to it. He can play the piano, but doesn't say who it was that taught him, claiming that "he is dead now." He acts cold towards Mikuzu, claiming that even though he doesn't like Mikuzu, he doesn't mind being around her. He's only shown her a true smile at the end of the book for a second. Kagari only allows Seto to treat him like a dog and use him as he wills. (Source: Wikipedia)