Genjui Toteku

Genjui Toteku (幻獣医トテク, lit. "Mythical Creature Doctor Toteku") is a one-shot manga by Hitsuji Gondaira. It was serialized in Weekly Shonen Jump.

Plot
Werewolves, vampires, dragons, and all sorts of other mythological beings are real, and they live hidden among us. But in order to stay hidden, they need special doctors who can treat them without having to worry about their true natures being revealed. Toteku Tatsumaki is one such doctor, a young yet brilliant human boy who has genetically altered his own body to better be of service to the supernatural community.