Welcome to Demon School! Iruma-kun

Suzuki Iruma is too nice and just doesn’t know how to say no. One day, he somehow gets dragged into the netherworld where the demons live. He arrives at the great demon Sullivan’s mansion where he is asked to do the unthinkable... and ends up becoming Sullivan’s grandson! He is quickly enrolled into the Demon School Babyls where Sullivan serves as chair-demon. Iruma begins his super exciting school life at demon school while trying to conceal the fact that he’s a human!

Iruma, who is going to Babirusu, wants to spend calmly so that he will not be noticed by humans. However, the entrance ceremony and a case with the entrance examination chief Asmodeus Alice have already attracted the attention of the students! First-year students Iruma and others decided to participate in the "Familiar Summoning Ceremony" event to determine the rank of the devil. The person in charge is Naverius Caluego, an extremely strict instructor in Babiru's. What kind of familiar is Iruma summoned?

Part A: Iruma and Asmodeus encounter a rather strange girl named Valac Clara. Because of her friendly yet strange demeanor, some students seem to be taking advantage of her... Part B: Iruma had become closer to both Asmodeus and Clara. They started picking him up from his house to walk to school together and Iruma was still trying to get used to demon life. One day at lunch, some kids try to pick on Iruma, but...

Iruma, Asmodeus, and Clara end up in the Misfit Class. As the name suggests, the class is filled with a bunch of misfits and Sabnock Sabro, who wants to become the next Demon King, declares Iruma his rival. Their classes start and their first lesson is a flying race. The race was to take place in the Warbling Valley and the Cutthroat Valley. Apparently, there’s also a demon bird that lives there...

The Misfit Class is in the middle of a flying race in order to determine their ranks. Since Iruma is human, he can’t fly, so he’s riding on the back of the giant baby demon bird, but it seems to be flying off course. Meanwhile, Sabnock decides to go through the treacherous Cutthroat Valley and ends up having to battle it out with the Guardian there. Sabnock is obsessed with becoming the next Demon King, but why is he so obsessed? Are Iruma and Sabnock going to be able to make it out of Cutthroat Valley alive?

Iruma obtains the Gluttonous Feeder ring which feeds upon the magical powers of others. Iruma is still doing everything he can to not stand out at school, but an incident occurs in class involving the ring, which ends up bringing even more attention to him again. Meanwhile, a certain demon was wondering if Iruma was actually human. That demon just happens to be the student council president, Azazel Ameri. But there’s a very unique reason that makes her think Iruma is human...