Sasahara Natsuki is a destitute bounty hunter in a world where monsters and humans coexist. Most of her cases involve monsters violating the rights of humans, who are legally protected from their generally more powerful neighbors. Being half-human and half cat-beast, Natsuki straddles the two societies and tries to understand and respect both while enforcing the law. She is assisted by a werewolf named Batanen who is afraid to admit he loves her; another werewolf named Tommy; and a Kyubi fox demon named Sakura who has her own plans--which include eating Natsuki to complete her nine tails and thereby her magical powers.