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 layabout 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. In an effort to win Karin over, Anzu accidentally makes a deal with the devil, and all Hell breaks loose.