In Esen, a modern world where monsters survive and live in the wild, hunters exist. When a human turns 21 they receive their status and innate skill. No one knows why this happens. Innate skills determine a hunter. The type of hunter you become depends completely on your innate skill. Alonne is someone who leads a different type of 'killing job'. He is an assassin. He kills humans not monsters. When he turns 21 he turns into a small wolf and gets his innate skill: Evolution