Manga by author Dong Geulim

The Hero, who defeated the Demon King and saved the world, is being summoned to a shi*** delinquent school?!The otherworld Hero who was summoned to a den filled with the worst bullies ever, the Southern Suseong High'.Though the Hero doesn't use his powers against fellow humans, he begins to school these bullies after finding out about their demonic' nature!Can the Hero defeat the bullies and return back to his world?