In a world filled with superpowered Quirk users, college student Kouichi Haimawari's dream is to become a hero just like the ones he so admires. Unfortunately for him, he finds out that there is only so much he can do with a sliding ability that gives him about as much speed as a bicycle. Thus, he is drawn to extra-legal, simpler work and takes on various local tasks beyond the grasp of the police and licensed heroes. However, a chance encounter with two misfits, a brash brawler vigilante who goes by Knuckleduster and the online sensation PopāStep, gives Kouichi the opportunity he has always dreamed about. With a dangerous new Quirk-enhancing drug turning ordinary people into instant villains, Kouichi finds himself accompanying the two in a quest to stop the drug from spreading. As the trio tries to get to the bottom of the case, the chaotic team looks to put a stop to wrongdoers that go overlooked by the law. [Written by MAL Rewrite]