one punch man - king wet his pants

On a supercontinent version of Earth that has four Moons, powerful monsters and villains wreak havoc. The millionaire Agoni creates the Hero Association, which employs superheroes to fight evil. Saitama, an unassociated hero, hails from City Z and performs heroic deeds as a hobby. For three years, he has trained enough to defeat any enemy with a single punch, his unmatched strength leaving him bored. He becomes a reluctant mentor to Genos, a cyborg seeking revenge against another cyborg who killed his family and destroyed his hometown, after Saitama defeats a monster that defeated Genos. Saitama and Genos join the Hero Association, hoping to attain notability, but Genos instantly obtains an S-Class rank; meanwhile, due to scoring low on the written exam despite having a perfect score on the physical exam, Saitama only becomes a C-Class hero. His feats remain unnoticed even after saving people from an asteroid and then a sea monster, barely getting himself promoted to B-Class. Later, shortly before her death, the seer Shibabawa predicts that the world is in great danger as the alien Boros invades the planet. The heroes kill the invaders and destroy Boros's ship as Saitama defeats Boros in single combat. Monsters begin appearing faster while the rogue martial artist Garo, a former apprentice of the hero Bang, and self-dubbed "Hero Hunter," begins terrorizing heroes. Due to childhood bullying, he holds a grudge against everything "heroic." The heroes learn that the monster influx comes from the Monster Association, an organization of monsters under City Z intent on destroying the Hero Association. They attack various cities, recruit fighters by offering them "monster cells" that mutate humans into monsters, and kidnap a Hero Association executive's son. Garo bonds with Tareo, a child who idolizes heroes, as he hunts down more heroes, his combat prowess slowly rising. The Monster Association attempts to recruit him and kidnaps the child when Garo refuses.