Childhood friends Matsuri Kazamaki and Suzu Kanade share a unique bond: they can both see and interact with ayakashi, supernatural beings that feed on life force. However, as they progress through high school, their once-close relationship begins to falter. Suzu's unrequited love for Matsuri deepens and she embraces her identity as an ayakashi medium, someone who exudes excessive life force and is therefore at greater risk of being targeted by ayakashi. Meanwhile, Matsuri grows increasingly apprehensive of all ayakashi, seeing them as a threat to his friend.
Their fragile dynamic is further complicated when they encounter an elderly white cat named Shirogane, unaware that he is actually a four-hundred-year-old ayakashi known as the "King of Ayakashi." Shirogane seeks to gain even more power by devouring Suzu, but when Matsuri tries to intervene and seal Shirogane's powers, the ayakashi instead transforms him into a girl!
Now, Matsuri must learn how to navigate the world as a girl and protect Suzu in this unfamiliar form until his grandfather, a renowned wind jutsu exorcist ninja, can undo the jutsu. At the same time, Suzu must grapple with her feelings for Matsuri, now complicated by his newfound femininity. To further complicate matters, Matsuri decides to adopt Shirogane as his pet, leaving the future of their friendship uncertain.
