In a world where ayakashi, mysterious beings invisible to most, pose a threat by draining human life force, exorcist ninjas like Matsuri Kazamaki safeguard the populace. Born into a respected ninja clan, Matsuri's childhood friend Suzu Kanade possesses the rare gift of attracting ayakashi due to her abundant vitality. While Matsuri is determined to shield Suzu from these malevolent spirits, she feels drawn to them. Their lives take a dramatic turn when they encounter Shirogane, the formidable 'King of Ayakashi,' set on consuming Suzu. In a daring rescue, Matsuri seals Shirogane's powers but suffers an unexpected consequence—transforming into a girl! As Matsuri grapples with this strange change and battles hostile ayakashi, Suzu faces inner turmoil over her evolving emotions for her transformed friend, casting a shadow of uncertainty over their bond.