Isekai Yankee Hachiouji

A high school student named Shinichi dominates his local area by defeating rival gangs with ease. Bored by his lack of challenges and burdened by family responsibilities, he seeks stronger opponents. He and his friends are abruptly transported to a fantasy world where conventional combat is insufficient against the threats they face. Shinichi resorts to using a chainsaw to fight an evil creature. A villager believes them to be the prophesied heroes destined to defeat the God of Evil. Shinichi is pleased to finally encounter a worthy challenge.