Matsuri and Suzu have been friends since childhood and both have the ability to see ayakashi—youkai that feed off of life force. In high school, their relationship begins to change. Matsuri thinks all ayakashi are a threat to Suzu, but she loves ayakashi despite the danger.
One day, they find a talking white cat named Shirogane. He is actually a 400-year-old ayakashi, and he wants to devour Suzu. To protect her, Matsuri attempts to seal Shirogane's powers, but the ayakashi casts a spell on him and turns him into a girl! Now, Matsuri must find a way to undo the spell and Suzu must confront her feelings for Matsuri now that he's a girl.