|“||I'm just a guy who's a hero for fun.||„|
|“||100 push-ups, 100 sit-ups, 100 squats, and a 10km run EVERY SINGLE DAY!!!||„|
|~ Saitama describing the secret behind his power|
He is registered with the Heroes Association as a B-Class Superhero (A-Class in the webcomic) and is tasked to defend Z-City against Mysterious Beings.
Saitama is a slim, bald man of average eyes. He notably wears a yellow jumpsuit, with a black belt, round, gold buckle, white collar, short zip, red gloves, red boots and a cape (red in the manga, white in the anime) that is attached by dark grey buttons.
Saitama is drawn in a simpler style than other characters in the series, having an oval-shaped face, and a simple mouth and eyes. However, when drawn in a more serious style, with more detail, Saitama is revealed to have sharp features and a muscular body.
Saitama initially had messy, black hair and brown eyes, but claims to have lost all of his hair, suddenly, as a result of his intense hero training.
For a superhero, Saitama is thought to be quite indifferent. Even the mightiest foes pose no challenge to him, so he doesn't take his hero work very seriously and defeats monsters as if as he is swatting insects. Since his superhero work has begun to bore him, he is constantly searching for an opponent that can actually provide him with a challenge. The lack of any such opponents has led him to suffer from a self-imposed existential crisis, and he claims that his ability to feel any and all emotions has dulled considerably. He stated that he just became a hero because it was his dream and for self-satisfaction and that before becoming one, he used to suffer from anxiety issues. Despite his boredom, Saitama goes out of his way to stop crime.
|“||If the Heroes run and hide, who will stay and fight?||„|
|~ Saitama to Genos|
The combination of his attitude, unstoppable strength, and distinctively simple and "unimpressive" appearance frequently cause his battles to become anticlimactic. Saitama will usually allow his opponents to rant/gloat about their motives and power up into their strongest forms before obliterating them with a single punch. However, if they begin to ramble on too much then he will either interrupt them or just punch them.
A running gag about Saitama is his inability to remember certain people's faces and names, as seen when he forgot Sonic's name and could not remember who Tanktop Tiger was. Because of this, he always ends up pronouncing their names incorrectly.
As of some special chapter during his time participating a costume contest, appearances don't matter to him. The only thing that matters to him are his abilities and his desire to be the superhero he's been training for. That being said, he does care about his own cleanliness, as the only thing he ever really complains about is how he gets dirt on his clothes or blood on his gloves. Though he usually doesn't care about appearances, he has shown dislike towards his assigned hero name, Caped Baldy. Thus, even after receiving it, he always refers to himself as Saitama.
Saitama has been shown to be very humble, as he deliberately let the masses turn against him, for the sake of the defeated heroes to be given credit for their efforts, even claiming that they had weakened the Sea King before his arrival. He did the same for the police in the Special Chapter, dressing as one of them and killed a monster, despite potentially gaining much fame had he revealed who he actually was. He also didn't mind that King took credit for all of his achievements.
Another unusual thing about Saitama is that he is surprisingly tactful and insightful, being well able to discern situations and character traits from the people and environment around him fairly easily. Having picked up a number of hints to Sonic's own persona on their first meeting and when two tank top heroes jealously plotted to ruin him after the meteor event that there were irate and self-serving hero types like them, as well as discerning Fubuki's forced offer of submission or destruction just before his crackdown on how the hero world really works than how it is currently run.
Saitama has been shown to feel empathy for his enemies before, particularly ones who can give him an actual fight and don't go down in one hit. One such example of this being Boros, for whom Saitama sympathized with him due to suffering from similar circumstances. Though in the end, Boros still couldn't draw out Saitama's full power.
Saitama does not actually care if people insult him and he usually ignores them and says that they need a hobby; the only insult that could at the very least get a what could be called reaction out of him is when anyone mentions/makes comments about his bald head. He also shows a measure of concern when it comes to bargains and deals, as seen when he fought Carnage Kabuto, when he was more shocked upon the realization that he was going to miss a bargain sale, rather than his opponent, who had undergone a transformation and was whacking him around. Despite his general indifference to most things, Saitama was genuinely shocked when he realized that no one actually knew of him, despite his achievements (although this could be attributed to the fact that he never stuck around after saving the day).
Saitama shows impressive restraint with his power, considering that he is easily capable of splitting the sky, or jumping from the moon to earth. He manages to beat nearly all of his opponents with a single punch, though occasionally causes more devastation than necessary. While he has no problem killing monsters, Saitama has yet to be seen killing another human, and only ever uses enough strength to knock them out, which still results in them ending up either being severely or critically injured.
Despite his willingness to give the credit to other heroes and not being a hero for fame or glory, Saitama has been shown to enjoy the few moments of fame when he is moved up, such as when he was shocked at the drastic promotion from the lowest C-class to the high C-class. Saitama also expressed jealousy when it turned out that Genos was listed in the top 5 handsomest heroes in the Hero Association and was the 6th most popular hero.
A very fatal flaw of Saitama is that he get extremely furious whenever he loses or is unable to get something done properly. In fact, Saitama nearly killed Bang, one of the top members of the Hero Association, simply because he couldn't control his anger at losing a trivial game. In his dream, he yelled to the Subterannean people that he never loses, further implicating this negative aspect of himself.
Hence his moniker, Saitama is the titular character of One-Punch Man and the strongest character in the entire franchise. So far no enemy has been able to injure him in any way and almost no enemy is even able to survive from a single earnest punch from him. A few enemies have survived punches from him, such as any human he has struck (which he was likely holding back against, like he always does) and Boros, whom Saitama empathized with and held back against so as to give himself and Boros a satisfying and stimulating fight. Saitama's only power is that his body is far beyond human limits, allowing him to achieve astounding physical feats. His strength is very formidable that it vastly eclipses even artificial beings designed or bred specifically for superhuman combat, such as mechanical beings or the mutated warriors from the House of Evolution. Since no enemies have posed any real challenge to Saitama yet, the upper bound of his strength is likely extremely higher than it appears. While his power is only limited to heightened human traits - Saitama cannot fly or project - his abilities alone more than make up for the lack of variety in his powers. His abilities are so powerful that they even eclipse those of the highest of superhuman abilities by leaps and bounds.
The origin of Saitama's immeasurable strength remains mysterious and unclear. Although he tells everyone he got his incredible power through mere physical training, no one believes him at all. According to Saitama, after a year and half of 100 daily push-ups, sit-ups, and squats, plus 10 km daily running, he had achieved some level of superhuman strength. This training was apparently so intense for Saitama that he at times felt he might die, and claims that it is what caused all of his hair to suddenly and eventually fall out. He apparently continued his training for another year and a half before beginning his hero career. Genos believes that Saitama doesn't actually know or understand how he gained his power, and hopes to learn the secret by sparring with and observing him, while Dr. Genus (on the other hand) believes that Saitama worked out with said training regimen so hard that he had removed his natural limiter completely, granting him access to unlimited power. It should be noted, that Saitama would complete all parts of the training one after the other without breaks and was battling mysterious beings that appeared during that time, which would have made completing the training more intense than would normally be expected.