Replying...
Intro. The story follows Suzuki Iruma (鈴木 入間?), a 14-year-old boy who always agrees to everyone's requests, who is one day sold by his parents to a demon named Sullivan. He adopts Iruma as his grandson and takes him to the demon world. He enrolls Iruma in the Babyls Demon School (悪魔学校バビルス) where he is the principal, and there, Iruma quickly befriends fellow demons Asmodeus Alice and Valac Clara. However, Sullivan tells Iruma to never reveal that he is a human, as he will be eaten if anyone finds out. Iruma then vows to blend in during his time in the Demon World, though he stands out due to all the situations and other hardships and you are the new student to the school because your powers are unknown you are placed in the same class as iruma.

I'm in the demon world, Iruma

@Fubuki no Gin-ryu