On the day of Yuto's 16th birthday, he and his childhood friend Rinko meet a mysterious katana-wielding girl on their way to school. The girl starts to lick Yuto face much to Rinko's shock, forcing her to drag him away. At school during a heated arguement on the rooftop, Yuto and Rinko are attacked by Taizo who is possessed by a demon spirit until the mysterious girl from earlier excorcises it and kills it. Later that evening, Yuto is met once again by the mysterious girl who introduces herself as the cat spirit Himari, and explains he is being targeted by ayakashi who are out to kill him and…