One Punch Man is an animanga series that has redefined the shonen genre and the usual superhero trope. It has done this by giving us a protagonist who is too powerful from the beginning. Saitama, the bald hero who can defeat any opponent with a single punch, was a revolutionary concept when the anime first aired in 2015.
While this concept was refreshing and many fans loved the story, some pointed out something unexpected: Saitama in One Punch Man might be the least interesting part of his own story. It turns out that his character does not have further narrative to him. He has already reached the top. There is no goal, no upward trajectory, no looming threat that challenges him.
Because now that he is canonically the strongest, nothing is left that excites or challenges him. Therefore, to make this story interesting, the creator makes a world where the side characters have their distinct arcs and showcase their struggles.
Before diving into why side characters are given more attention, it is important to acknowledge Saitama’s role. His presence disrupts the typical power-scaling, underdog storytelling that defines the genre. Saitama’s entire character arc was essentially completed before the story even began.

He trained so hard that he is the strongest man. The only downside to gaining this type of strength is that his story is one of existential ennui, not growth or struggle. To make Saitama’s uniqueness stand out, other characters must be written with contrasting traits. Because it would make him stand out, and these side characters would essentially be the reason to drive the plot forward.
One of the most telling things about One Punch Man’s structure is how little screen time Saitama gets in later arcs. In the current manga arc, he is barely a factor until the final act. He doesn’t influence major decisions. He doesn’t drive any emotional stakes.
This should not be mistaken for lazy writing — rather be given more attention as it is intentional. Because not the story highlights how dependent the series is on its supporting cast. Even though this format has been working for all this time, there is one danger to it.
Some fans have expressed disappointment that Saitama feels more like a cameo than a central figure. They miss his presence in One Punch Man, his deadpan humor, and his unexpected wisdom. That’s fair. At times, the balance does tilt too far in favor of the supporting cast.
Why did side characters become essential in One Punch Man?
In most stories, it is the protagonist who is the emotional core that drives the plot. And they are the ones who keep the audience hooked to the story. But in One Punch Man, Saitama is deliberately written as bored, invincible, and emotionally detached because if the story just revolved around him, it could get boring.
Additionally, having such a wide cast of side characters allows the writer to explore a variety of backstories, ideologies, and emotional journeys that wouldn’t be possible through Saitama alone. From Garou’s moral grey zone to Bang’s remorseful mentorship, each character brings a unique lesson or theme to the table.
Let’s look at some key examples: Characters like Genos, Garou, Fubuki, and Bang offer what Saitama cannot — tension, growth, and vulnerability. Genos gives us tragedy and grit, Garou introduces philosophical conflict, and Fubuki adds internal politics and emotional depth.
Their struggles and arcs provide stakes and progression, which Saitama’s one-punch victories can’t deliver. They carry the narrative weight, giving the world around Saitama purpose and texture.
In conclusion, One Punch Man began as a parody, poking fun at shonen tropes but as the story developed it embraced the same tropes in a unique way. Ultimately, sidelining Saitama may have been a brilliant creative decision, and now this animanga series could be a satire and a legitimate drama at the same time. And, maybe this is why the series worked is became popular worldwide.