Ult was born as half-beast and human in a world where beasts and humans are in conflict. He spent his days being looked at with contempt by those around him. His dream is to fulfill the wish of his best friend Leo, the only person who recognizes him as an equal, to ``kill the beastman who killed his sister.'' Therefore, even though Ult is a half-beastman, he dreams of joining the anti-beastman force ``Narukami'' in order to make Leo's dream come true. However, on the day of the enlistment exam, Ult is forced to make the ultimate choice in order to make his dream come true.