In My Hero Academia: Vigilantes, Kouichi Haimawari has spent years telling himself that being a hero is no longer within reach. A dull college student with an ordinary life, he still admires the idea of helping people, even in a world where 80% of the population has superhuman Quirks and only a small number of people are chosen to protect the public as licensed heroes.
When a street encounter brings him into contact with the vigilante Knuckleduster and the energetic Pop☆Step, Kouichi is drawn into a shadowy side of hero work that operates outside official approval. As they confront threats that licensed heroes cannot always reach, Kouichi is forced to decide whether his abandoned dream can survive in a world where justice is not always delivered by the law.