Return of the Hero

Heading home from shopping, Saitama and Genos cross paths with King, the S-Class Rank 7 hero whose mere reputation makes Tongue Stretcher surrender on the spot. A combat robot called G4 then challenges King and, when granted a delay, threatens to slaughter nearby civilians unless he returns within ten minutes. The truth spills out: King is no living legend but an ordinary otaku who kept receiving credit for monsters that were destroyed near him and embraced the fame. Rather than fight, he flees home to his dating sim, only for Saitama to follow and end up playing games alongside him. When the Giant Crow attacks and King wets himself in panic, Saitama kills the bird, prompting King to realize it was Saitama who once saved him from Octopus Claw Man, the monster that scarred his left eye.

While Saitama and King keep gaming, Genos defeats G4 and receives upgrades from its salvaged parts through Dr. Kuseno. Sitch announces that the Association will begin recruiting criminals to fight monsters, citing the rising frequency of attacks and Shibabawa's looming prophecy. Speed-o'-Sound Sonic walks out of the meeting once he learns Saitama is absent, having attended only to face him. In Z-City, Fubuki discusses Saitama's suspicious rise through the ranks with Eyelashes and Mountain Ape before setting out to find him. The episode ends with Garou declaring that a slaughter is about to begin.

King is exposed as an accidental hero who cannot actually fight, and his history with Saitama is revealed. Genos defeats G4 and is upgraded, Sitch sets the criminal-recruitment plan in motion, and both Fubuki and Garou are established as forces heading toward Saitama.

The opening scene of Saitama and Genos walking with groceries past a King action figure is original to the anime, as is King noticing Genos' fight with G4 while he flees. King's inner monologue about attracting monsters is trimmed to feature only Vaccine Man and Marugori, and several scenes, including Sonic leaving the base and Fubuki entering Z-City, were shifted into this episode. Garou's fight at the Hero Association base was pushed to the following episode, with only a brief post-credits tease here.