In the year 3XXXX humanity's numbers have dwindled to only a couple thousand. In order to save themselves from extinction, humans have injected a serum into their bodies that give them the attributes of wolves. As a result, there are no more full blooded humans and the world is run by "half breeds". These half breeds...
Levi Ackerman resides in a facility for the terminally ill, angry and bitter toward the world for being stripped of his life before he's even allowed to live it. He keeps to himself and in fact shuns any kind of social interaction with anyone. That is, until he stumbles upon the music room, inhabited only by a cancer...