Precocious tween Karin finds herself abandoned by her father in rural Japan. Living in a temple with her grandfather, she meets Anzu, a giant "ghost cat" and notorious lay about tasked with looking after her. Distrustful of her new guardian, Karin sabotages Anzu's odd jobs for the townsfolk and befriends the eccentric local forest spirits. To win Karin over, Anzu accidentally makes a deal with the devil, and all Hell breaks loose.