Childhood friends Matsuri Kazamaki and Suzu Kanade are connected by their common ability to perceive ayakashi, which are youkai looking for a life energy to consume. However, their friendship suffers throughout high school. Matsuri views all ayakashi as a threat to his friend, whereas Suzu is an ayakashi medium—someone who exudes a significant amount of life force compared to the average human—and loves them all despite the risk. As Suzu's one-sided feelings for them all grow, so does the gap in their perspectives on ayakashi. The "King of Ayakashi," a four-hundred-year-old ayakashi, is hell-bent on obtaining even more power by consuming Suzu, but as Matsuri swoops in to try to save her, the two are unaware that he is a talking white cat named Shirogane The ayakashi instead performs a jutsu to transform Shirogane into a lady by securing his abilities! As Suzu's closest friend, Matsuri swears to shield her from danger, but until his grandpa, a renowned wind jutsu exorcist ninja, can reverse the jutsu, he must learn how to behave like a lady. Suzu, meanwhile, needs to sort out her feelings for Matsuri now that he is an adult male. The future of the two buddies, however, becomes uncertain when Matsuri adopts the king as his pet.