On a starry night during summer time, high school 2nd year student, Amano Misora (Name changeable) saw a shooting star with classmate Satsuki Subaru. That night Misora met a UMA which appears in the form of a black cat called Nyagomaru, who asked Misora to help retrieve Anima Stone which causes human to grow animal ears and tails. The next day, discovered that your classmates and your teacher seems to have possess this characteristics.

In searching for the way to return to normal, Misora is attacked because of her pendant from her grandma and they discovered a bigger secret behind the reason for their transformation...

[from Nabari no Blog]