WARNING: The following contains spoilers for the Season 2 premiere of One-Punch Man, available on Hulu now.
One-Punch Man is set in a world full of superheroes who defend the populace from monsters, and the members of renowned Hero Association are ranked based upon their acts and reputed power levels. With most of his incredible feats largely unnoticed by the public, Saitama isn't the top-ranked hero, or even in the top class, the coveted S-Rank. Instead, the top-ranked superhero at the beginning of Season 2 is a scarred fighter known as King. And it's in the season premiere that Saitama and King finally sit down and reveal the truth about each other.
The first hero shown in the premiere, King is seen buying video games in town when he encounters the reptilian villain Tongue Stretcher harassing women. When the hero makes his presence known and begins to power up through his signature King Engine, Tongue Stretcher surrenders rather than risk annihilation. As King continues to make his way back to his apartment, he crosses paths with lower-ranked heroes Saitama and Genos, only to be confronted by even bigger threat: the towering robot G4.
Before the fight can begin, King excuses himself to go to the bathroom under the promise that he will use his full strength against the killer robot. It's then that the truth about King is revealed: Instead of being a powerful fighter, King is actually a simple man who happened to be present when several gigantic monsters were destroyed, and took credit for their defeat. Revered for his alleged role in saving the city on multiple occasions, King was given the Hero Association's top position, reveling in the fame and prestige while developing the King Engine as a grandiose bluff.
Leaving Genos to fight G4 instead, King furtively flees back to his apartment to play his adult video game, only to be surprised by Saitama who had secretly followed him back home. Saitama joins him in playing a video game, only to ask him if he fled the earlier confrontation, hoping to find a kindred spirit in another hero bored by facing enemies exponentially below his own power level. Before King can answer, the duo is attacked by a monstrous bird ramming itself into the top-ranked hero's apartment.
After effortlessly dispatching the bird with his signature single blow, Saitama notices King cowering in fear, having urinated all over himself. It's then the B-Class Hero realizes King's reputation has been a front. King even confesses to taking credit for many of Saitama's accomplishments to bolster his own standing. After Saitama urges him to improve himself for his own sake, King realizes it was Saitama who saved him from the monster that gave him his facial scar years earlier, and recognizes the unassuming hero as his clear superior.
In meeting the man reputed and ranked to be the strongest superhero in the world, Saitama found a disappointing fraud when he was hoping for additional guidance. Still, unbeknown to Saitama, he is the true strongest man in the world and inspires King to be true to himself and grow more powerful of his own accord to live up to his reputation. While the meeting does not live up to Saitama's hopes, it does provide more insight into his heroic nature, as he displays compassion and wisdom even to cowards taking credit for his work.
One Punch Man is produced by J.C. Staff. The subtitled version of Season 2 is set to premiere in the United States on Hulu on April 9 with new episodes debuting every Tuesday.