Blackwings; A Devil Princess' Adventures on the Surface World

Grey is just your typical, average high school student who joined the Occult Club but became part of a laughingstock because it’s been stated that all their club activities are nothing but a hoax. Days had passed and the members left, leaving him alone in the club. One day, he found some old notes from the club’s alumni members. He decided to leave the club for good after doing the note’s last activity—summoning a devil. He’s certain that it’s going to fail anyway but, after a single drop of blood, an unexpected event has occurred.