Welcome to Demon School Gon and Iruma!

Gon accidentally signs a contract which sells him to the Demon Sullivan who wants him to be his grandson with a boy named Iruma. At first, he wants to get back to his family, but he wants to at least give Sullivan-san a try and give Iruma a kind cheerful point of view of this new life. While in Demon School Iruma and Gon are going to have lots of challanges.