A teacher has been invited to teach in a high school. While he enters the school, He meets a girl asking for help. It turns out that her servant went on a rampage and started destroying the school. They tried to stop it but couldn't. Suddenly, a mysterious person came out to help them and solve the problem. After that, he finally noticed the girl's real identity, which is a vampire! At this moment, when he knew, he realized he had been invited to a high school full of fantasy creatures.