The Hero Defeats the Bullies

The hero who saved the world by defeating the demon king is summoned to a toilet bowl gang school?! A hero from another world summoned to the worst gang gathering place, "Suseong South High School." Although he is a hero who does not use his power on humans, he faces the reality of bullies like "demons" and starts true education...! Can the hero defeat the bullies and return to his own world?