The Festive Monster's Cheerful Failure

Ikuya Magasa is a freshman in high school with no dreams or particular interests, and so he just lets the days pass by.
On their way home one day, his friend Kaze Amaba makes a shocking confession.
"Truth is, I'm a tengu."
Amaba had longed to live in the world of humans, and in order to remain there, he invites Ikuya to start a band.
From then on, Ikuya's normal days started to become more and more abnormal?