Teenager Kazamaki Matsuri has long been part of an elite force of ninja exorcists, tasked with fighting malicious ayakashi spirits who threaten Japan–especially those after his childhood friend, the spirit medium Kanade Suzu. As he fiercely protects her, and his relationship with her blooms from friendship into something more, a powerful cat ayakashi vows to get between the lovebirds: by casting a forbidden spell that turns Matsuri into a woman! With no apparent way to undo the spell, Matsuri must continue battling ayakashi–and go back to school–in this new feminine body until he can find a way to turn back.