|Abilities||Superhuman Strength, Speed|
|Affiliation||The Heroes Association|
Saitama (サイタマ, Saitama) is the main protagonist of OnePunch-Man, and the most powerful hero alive. Having apparently trained himself to superhuman condition, Saitama faces an existential crisis as he is now too powerful to gain any thrill from his heroic deeds.
Saitama is a bald man with a thin, but well-built physique and of average height and weight. He claims to have lost all of his hair suddenly and prematurely as a result of the toll taken on his body by intense hero training. Three years before the storyline, Saitama had spiky, black hair. Saitama's eye color is unclear, as his eyes are usually represented by dots.
Saitama is usually deliberately drawn in a simpler style than other characters, with a very rounded head and only a simple mouth and eyes. When drawn in a more 'action-oriented' style with more detail, Saitama is revealed to have sharp features, dangerous looking eyes, and a chiseled musculature. His costume is a plain yellow jumpsuit with a short zipper at the collar and a belt. The costume is finished out by a red ensemble of boots, gloves and a cape.
For a superhero, Saitama is rather laid back. Because even the mightiest foes pose no challenge to him, he doesn't take his hero work very seriously. In spite of this, he is constantly searching for an opponent that can challenge him, since his superhero work is beginning to bore him because it's too easy. However, Saitama does not ignore crime despite his boredom, as in his own words (having displayed a lack of understanding at the disaster level system), "If the heroes run and hide, who will stay and fight?".
The combination of his attitude, unstoppable strength, and distinctively simple and 'unimpressive' appearance often cause his battles to become anticlimactic. Saitama will usually allow his opponents to rant about their motives and power up into their strongest forms before suddenly and nonchalantly obliterating them with one punch.
Three years before the current storyline, Saitama was an unemployed 'salaryman' on a job hunt. One day, after yet another failed interview, a nihilistic-feeling Saitama was wandering the streets and encountered Crabrante. Saitama's total apathy toward the situation impresses Crabrante, who claims to share a similar outlook, prompting him to spare Saitama and move on. Crabrante tells him that his real prey is a child with a cleft chin anyway.
Walking on, Saitama spots the child Crabrante was talking about. He decides that he doesn't want anything to do with the matter but after Crabrante suddenly arrives, Saitama impulsively saves the child from Crabrante's attack. He urges the child to run away and demands to know why Crabrante wants the boy dead. While Crabrante explains the prank the boy pulled on him, Saitama chuckles and notes aloud how the monster resembles one from an anime Saitama watched in his youth. This enrages Crabrante, who pummels Saitama even after the latter resolves to live out his childhood dream of being a superhero by fighting back. As Crabrante turns from the apparently defeated Saitama to finish the cleft-chinned boy, Saitama lassos one of his eye stalks with the loop of his removed tie and tears it out. The monster is defeated and the child saved.Resolving after this encounter to become a mighty superhero, Saitama started a daily training schedule which consisted of 100 push-ups, 100 sit-ups and 100 squats along with running 10 km every single day. He ate three meals a day, but only a banana as breakfast and also didn't use the AC, to strengthen his mental resistance. These daily activities were extremely tough and caused his body excruciating pain; muscle aches and internal bleeding. However, Saitama didn't give up and continued his training day after day. After a year and a half, he had become strong. But as a side-effect, Saitama had also lost all of his hair. He continued his training for another year and a half before starting his (initially amateur) superhero career.
Magicicada Larva AttackEdit
Some time between when Saitama started training and when he started to lost his hair, Z-City experienced a Mysterious Being attack by the 170,000-Year Magicicada Larva, prompting the citizenry to evacuate to the state-of-the-art Shelter Nr. 7. The three low-ranking heroes sent to defeat the Magicicada were defeated, but survived and managed to find some straggling evacuees on their way back to the shelter, among them being Saitama.
When Saitama discovers that he has been led to a shelter, he becomes upset, stating aloud that he thought that following the heroes would lead him to the Mysterious Being. Saitama attempts to leave so he can find the Mysterious Being, but is restrained by the citizens, thinking he's become suicidal. The guards attempt to explain that the doors can't be opened while the disaster is still ongoing, but reassure the public that the shelter is able to withstand any sort of attack. While she praises the structure's perfection, Saitama confronts one guard again to ask where the bathroom is, only for her to reply that the 'perfect' shelter was nevertheless designed and built without bathrooms.Saitama slowly becomes more and more distressed, as he doesn't know if his bladder can hold until the situation ends. After overhearing that two A-Class heroes were defeated by the beast, and that it will take three hours for a Heroes Association squadron to arrive, Saitama can't take it anymore. He walks to a wall of the shelter and breaks a hole in it with a single punch before the stunned onlookers, and runs off stating that he's going to the convenience store. Just as he is about to reach the store to use the bathroom, the 170,000 Year Magicicada Larva appears in front of him, which he promptly kills.
Introduction ArcEditSaitama first appears watching a news report on Vaccine Man attacking Z-City. Seeing the destruction, he remarks, "I should go...".
Saitama appears at the scene just in time to save a young girl from being killed. The monster is angered and asks who Saitama is, and he replies that he is "just an average guy who serves as an average hero". After reluctantly listening to the monster's angry monologue and watching its transformation, Saitama kills it with an effortless punch. After this, he screams out in frustration at another easy victory; a pattern which will be repeated in future battles.
Some time after, Saitama hears about a Demon-level disaster emergency, stemming from the Brain and Brawn Brothers destruction of D-City. After finding the duo, Saitama leaps onto the monstrous Beefcake's shoulder and tells him to put some pants on. Oldface, Beefcake's brother who is on his other shoulder, is shocked by Saitama's sudden appearance and orders his brother to swat him. However, Beefcake absentmindedly swats at the wrong shoulder, instantly killing his brother. Enraged, Beefcake grabs Saitama and throws him into the ground. Saitama is unaffected, but Beefcake continues with a frenzied assault of massive stomps and punches, creating a large crater. Believing he has killed Saitama, Beefcake moves away, only for the completely unfazed Saitama to dash out of the crater and crumple the giant's face with a single punch. Saitama states that having an overwhelming power is boring as hell, as the dying Beefcake topples over. Unfortunately, Saitama's blow causes him to fall on top of B-City and the town is destroyed.
House of Evolution ArcEditSaitama later is shown lamenting his lot in life: how every fight ends with a single punch and goes on to compare all his battles to swatting insects. As if to illustrate the point to himself, he delivers a mighty swat to a mosquito that has landed on his hand, but when he lifts up his hand the mosquito flies away unharmed. After unsuccessfully swatting at it several more times, it flies off and Saitama is left in a rage. The mosquito is then shown to fly off to Mosquito Girl. Afterwards Saitama sees a news story about a mass mosquito outbreak that is headed towards Z-City.
When Mosquito Girl raids the city, Genos makes his first appearance and starts to fight her and performs well for a while, but then she begins absorbing all the blood gathered by her mosquitoes. Saitama suddenly comes running around a corner on to the battlefield, in pursuit of the mosquito he'd been trying to kill. At that moment, Mosquito Girl finishes her blood-fueled evolution and sends her mosquitoes crashing down on Saitama and Genos, the latter of whom obliterates them all with a gout of flame. When the smoke clears Saitama is standing there naked and only slightly singed, thanking Genos for killing the mosquitoes.
The newly empowered Mosquito Girl starts attacking Genos and tearing him apart with her claws. Just as the heavily damaged Genos is about to resort to a self-destruct, Saitama suddenly slaps Mosquito Girl, sending her flying through a nearby building and into the sky. Dusting off his hands, Saitama remarks, "Man, I hate mosquitoes".
After witnessing Saitama's incredible power, Genos begs Saitama to make him his apprentice. At Saitama's house, Genos gives a long explanation of his past and motives, but Saitama is completely uninterested. Saitama agrees to take Genos on when he explains that he simply wants to be taught to become as strong as Saitama.
Meanwhile, the House of Evolution, having become interested in Saitama after he defeated their warrior Mosquito Girl, sends more of its creations to attempt to capture him. Manty arrives at Saitama's house first, crashing through the ceiling and immediately has his head punched off for the trouble. Saitama and Genos then go outside to meet the threat where they are confronted with Frog Man and Slugerous. Saitama promptly buries their heads in the ground complaining about how they made a hole in his ceiling. Suddenly, a hand emerges from the ground by Saitama's foot, grabbing his leg and dragging him underground, until only his head protrudes from the sidewalk. Genos begins to rush to Saitama's aid but is intercepted by Armored Gorilla. While Genos is fighting Armored Gorilla, Saitama is approached by Beast King.Beast King congratulates Ground Dragon on incapacitating Saitama but notices that the distinctly un-terrified hero is falling asleep due to how pleasantly temperate he found it underground. Beast King starts to get angry and threatens to scratch Saitama's eyes out, at which point Saitama simply steps free out of the ground. Beast King then attacks Saitama, who easily avoids his claws and slicing air currents, one of which kills Frog Man and Slugerous. Beast King is enraged that none of his attacks are hitting and goes berserk, sending a flurry of attacks at Saitama, who dodges them all before striking back with a short combo of punches. The attack obliterates Beast King's entire upper body, prompting a terrified Ground Dragon to run away by digging underground, but Saitama appears in front of him through a hole of his own making and punches Ground Dragon through the earth and up into the sky. When Saitama gets back to the surface, he finds that Genos has defeated Armored Gorilla and is questioning him. After Saitama shows Armored Gorilla the remains of Beast King he tells them all they want to know. 
Roughly four hours later, Saitama and Genos have climbed a forest path to arrive at the House of Evolution's base. Wasting no time, Genos destroys the above-ground portion of the base with an energy blast, surprising Saitama slightly with his ruthlessness. In the rubble they nonetheless find a metal door which leads to the basement. As they enter the subterranean portion of the lair, they are attacked by Asura Rhino , who discards his former 'master' Dr. Genus before embedding Genos into a wall and incapacitating him with a single, thunderous blow. Saitama is angered because Asura Rhino turned Genos into "modern art" and agrees to Asura Rhino's request for a fight.
The fight is about to start when Genos re-appears and attempts to fight Asura Rhino, but is beaten down again causing Saitama to step in to fight. Asura comments on how he can feel that Saitama is really strong, while Saitama tells him not to disappoint him, as he expects Asura to be the strongest being from the House.
Suddenly moving with tremendous speed, Asura Rhino appears behind Saitama and is about to strike him, but suddenly becomes extremely intimidated and leaps, back thinking to himself that if he had attacked at that moment he would have been killed. He explodes with rage and fear and orders Saitama to tell him how he got so strong. Saitama agrees to tell them and explains his method of 100 sit-ups, push-ups and squats and 10km of running every single day. Genos is outraged, stating that Saitama's strength would be totally impossible to achieve with that kind of routine strength training, while Asura Rhino is angered, thinking Saitama is mocking him.
Enraged, Asura Rhino enters "Asura Mode" and states that he'll stay in this form and go on an uncontrolled rampage for a week, "until next Saturday". Asura then begins to pummel Saitama, sending him flying around the room, while this is going on, Saitama comes to the horrifying realization that if "Asura Mode" lasts for a whole week ending on a Saturday, then it is in fact Saturday today and that he missed "special sale day". Suddenly overcome with despair, he cries out and obliterates Asura Rhino with one punch.
Paradise Group ArcEdit
Saitama is first seen waking up frantically from a dream involving someone pointing a snotty finger at him. Realizing it was just a dream he then turns on the news and finds out that the criminal Hammerhead and his terrorist organization known as the Paradise Group, consisting entirely of bald, dangerous looking men have arrived and started wreaking havoc. The news warns everyone to avoid any bald men with a dangerous aura. This angers Saitama who states that this group will ruin his image as everyone will mistake him for a villain. He resolves to destroy the Paradise Group to protect his image. Saitama heads out to search for the villains, and on his way many people end up mistaking him for members of the Paradise Group
On his search for the Paradise Group, Saitama finds himself lost in a forest. Trying to find a path out, he is halted when Hammerhead, recently defeated by the powerful ninja Sonic, appears rushing towards him. Hammerhead mistakes Saitama for someone wanting to join up with the Paradise Group, and Saitama tells him that he actually came to destroy them. Hammerhead swiftly attacks Saitama with a vicious punch but Saitama is unfazed and unimpressed. Enraged, Hammerhead charges up to full power and executes his windmill attack. Upon seeing this Saitama notices it looks much like an 'attack' he used to perform as a kid and wonders if Hammerhead is similar to him. He then stops the attack with little effort and shatters Hammerhead's battle suit with a quick punch.
After making him promise to never do bad things again, Saitama allows Hammerhead to flee. Shortly after, Sonic arrives demanding to know where Hammerhead has gone. Saitama points in the direction that Hammerhead fled and says, "He went that way. Naked." Sonic then attacks Saitama, mistaking him for a member of the Paradise Group, with a shuriken thrown at lightning fast speeds. However Saitama effortlessly catches both the shuriken and Sonic's subsequent attack with a sword and then proceeds to break the sword in half. Saitama then frantically explains that he is not a member of the Paradise Group and asks Sonic whether or not he recognizes him as the man who has saved the world many times. When Sonic says, "Nope, don't know you" Saitama becomes severely disheartened. Sonic then proceeds to attack Saitama, stating that the real problem here is that Saitama was able to see two of Sonic's attacks and that his pride cannot allow for Saitama to live. Upon hearing this, Saitama accuses Sonic of being a liar stating that Sonic just wants to test his attacks on him, indicated by the childish smile on Sonic's face.
After Sonic jumps around for quite some time, Saitama intercepts him and asks if he can go home now. Surprised, Sonic retaliates with a lightning fast kick, but Saitama attempts to interrupt his attack by placing his fist directly in the path of Sonic's genitals. However he accidentally moves his fist too far and taps Sonic's testicles. Sonic, clearly in pain from this accidental nut-shot, states that he will train day and night for their rematch and then flees. Later, Saitama is seen at his house going over the day's events with Genos. Saitama asks Genos to leave, stating that he is in shock due to a certain event that occurred that day. Genos, worried about anything that might shock Saitama, asks what it was and Saitama explains that he can't believe that Sonic had no idea who he was despite all his previous exploits. Genos then asks if Saitama was a registered superhero, to which Saitama replies in the negative. Genos then goes on to explain that anyone who hasn't registered with the Heroes Association will never be recognized for their feats. Saitama then resolves to become a licensed hero so he can achieve the fame he deserves.
National Superhero Registry ArcEdit
Saitama arrives at the 6th Official Superhero Certification Exam Center and begins a series of physical tests. Saitama does so well on physical tests that he awes the examiners and disheartens the up and coming superheroes from taking the tests altogether. Later in the waiting room, Saitama meets with Genos and the two discuss the easiness of the superhero qualification tests and state that there is no way they didn't pass. When the results of the tests arrive it is revealed that Saitama barely passed, having achieved a score of 71 when the required minimum was 70, and receives the C-class hero designation. Later it is revealed that Saitama achieved a perfect score in all the physical test and broke every record of the Superhero Association and the only reason his score was so low was because he did poorly on the written test.Later during a lecture from an A-Class hero named Sneck, Saitama is seen slacking off. This angers Sneck and, along with hearing the news that Saitama could quickly surpass him, causes Sneck to later ambush Saitama but Sneck is quickly and non-lethally dispatched.
Sometime later Genos apparently requests a sparring match with Saitama. Saitama having earlier agreed to take Genos as his disciple officially, under the condition that Genos register as a superhero as well, accepts Genos' challenge. The battle begins when Genos fires a massive energy attack which Saitama dodges with ease. Genos then proceeds to attempt to attack Saitama physically but eventually discovers he was chasing an afterimage the whole time. After an extremely close-range energy attack in which Genos believe he finally landed a blow on Saitama. Saitama, having dodged the attack and poking Genos' face, declares himself the victor, but Genos reminds him that the match cannot end until one of them is unable to continue. Upon hearing this Saitama appears in front of Genos and delivers a devastating blow that stops inches from Genos' face. Genos is unharmed but the landscape behind him is obliterated. Saitama and Genos then return home.
Five days later Saitama is seen lounging around his house reading a magazine. He then notices Genos, carrying a huge backpack full of contents unknown, who then requests to live with Saitama. At first he declines, but after Genos tells him that he will pay him rent Saitama allows Genos to stay with him. Genos later informs Saitama that all C-Class heroes who are inactive for a week are removed from the official registry. Saitama, realizing he only has two days remaining, sets out to find a villain, only to discover that Z-City is completely peaceful. Saitama decides he will check again the next day and returns home. Upon discovering that Z-City is peaceful for the second day in a row, he becomes greatly distressed. All of a sudden, a shuriken is thrown at Saitama, who catches it, and discovers that his would-be assailant is none other than Sonic.Saitama tells Sonic that he is busy and begins to walk away but Sonic rushes to intercept him. Frustrated, Saitama bites Sonic's sword, shattering it in the blink of an eye. He then explains again that he is busy and threatens that, if Sonic gets in his way again, he will punch him. At this time a woman from the crowd observes Saitama and states that he is a "Suspicious Person". Saitama, thinking that the woman was referring to Sonic, begins to lecture Sonic for being so violent. Then a C-Class hero, named Tanktop Tiger, explains that the woman was referring to Saitama. Saitama attempts to explain that he is also a registered hero but Tiger states that he has no idea who Saitama is and thinks that he should leave as he is ruining the reputation of other heroes. Saitama becomes increasingly annoyed but, before he has a chance to attack, Sonic launches a surprise assault on Tiger, who is defeated instantly.
Sonic then begins to wreak havoc on the surrounding civilians. During this chaos Saitama saves a small boy's life by effortlessly moving a tree in place to intercept a falling car that would have otherwise killed the boy. Saitama, angered both by the fact that he can't find a bad guy to fight and that civilians are in danger, realizes that Sonic is now considered a bad guy and decides to retaliate. Saitama appears behind Sonic and dispatches him with a single swift chop.
Demonic Fan Side StoryEdit
After Tornado leaves the fight against the Demonic Fan with Miss Blizzard Saitama shows up and notices that the Demonic Fan is not dead, but instead reforming itself. The young member of The Blizzard Group attempts to stop Saitama from going to attack the Mysterious Being, but Saitama goes anyways and easily destroys the Demonic Fan.
Rumored Monster ArcEditSaitama, apparently returning home from shopping, happens upon a scene where a monster has just dispatched two A-Class heroes in battle. Saitama remembers that he forgot to get kombu at the store and notices that this monster appears to be made of it. Later, Saitama is seen cooking kombu that was apparently taken directly from the monster's body. Genos reveals later that Saitama wanted to eat kombu to see if it could make his hair grow back.
Giant Meteor ArcEdit
Saitama and Genos are relaxing in their apartment, and Genos tells Saitama that he's been promoted from C-Class, Rank 388 to Rank 342, and while he hasn't been raised from S-Class Rank 17, he's been ranked 6th in popularity. Genos then gets a call from The Heroes Association and heads out.
Later, after Genos fails to destroy the Meteor, Saitama shows up and asks Bang to take care of Genos. He then launches himself at the Meteor and punches through it, causing it to break apart. Unfortunately the pieces of the Meteor then rain down on Z-City. Saitama then lands, looks around and says "Well, I guess that takes care of it," and walks off.
Three days later, Saitama and Genos are relaxing in their apartment again, watching a news report on how the Meteor fragments destroyed many buildings and businesses in the city. After learning that his rank had jumped up from C-Class, Rank 342 to Rank 5, Saitama gets excited and decides to go out for a walk around town. During his walk he gets called out by Tanktop Tiger, but Saitama doesn't remember who he is. Tanktop Tiger then declares that Saitama is a liar, that there is no way he would be able to destroy a Meteor on his own and that he merely took credit of the S-Class Heroes work. Saitama starts to defend himself but is cut-off by Tiger who calls out for his big brother, who then jumps in and introduces himself as Tanktop Black Hole.Black Hole claims that he has a perfect punishment for a "lying cheat" like Saitama. He then, in a rather loud voice, starts accusing Saitama of destroying the town. The commotion starts to attract citizens who begin to gather around the scene. Black Hole continues to accuse Saitama of destroying the town on purpose and slowly, the crowd begins to turn on Saitama, shouting out threats and accusations along with Black Hole. Black Hole then accuses Saitama of wanting to destroy the citizens, just as he "destroyed" the town, and then challenges him to a fight. Tanktop Tiger then rushes forward to attack Saitama, but gets easily knocked away into a pile of rubble, Tanktop Black Hole then jumps in and tries to grab Saitama. Saitama intercepts him and locks hands with Black Hole and squeezes, causing Black Hole to fall to his knees in pain and apologize for lying. Saitama then shouts to all the citizens that he did destroy the Meteor and that if anyone has a problem with him they should say it to his face.
Sea Monster ArcEdit
On his way home, Saitama comes across a Seafolk about to attack a city, so he defeats it quickly. Some time later, Saitama is relaxing as Genos does dishes and explains that Saitama has advanced to the second rank of C-Class. He goes on to explain that once Saitama becomes rank 1, he can go up to B-Class. Genos then starts talking about how the top ranking C-Class hero hasn't left his position for around half a year, which apparently is no match for the top ranking B-Class hero. Before Genos can finish talking about that though, he gets a call about an attack on J-City by more Seafolk. They turn on the news and watch part of a news report on the incident and decide to head out to help.
Some time between their leaving and their getting there, Saitama and Genos get separated. During his search for the Sea King, Saitama finds License-less Rider's cell phone lying in the street. Upon picking it up, the man on the other end of the line requests to know who he is speaking to and, despite Saitama only being listed as a C-Class hero, decides to disclose the location of the Sea King, apparently to finally determine just how strong Saitama is. Later, Saitama arrives at the shelter just in time to witness License-less Rider's defeat at the hands of the Sea King. He catches License-less Rider's unconscious body and tells him he fought well. He then observes the scene and is surprised to find that Genos is alive despite his grievous wounds. After remarking that he will quickly dispatch the Sea King, Saitama is attacked by the monster but he is noticeably unscathed.The Sea King declares his surprise that Saitama did not fall from his punch, but Saitama remarks that the Sea King's punch was simply too weak to hurt him. Meanwhile the spectators talk among themselves, telling each other that their situation has not changed at all with only a C-Class Rank 2 hero arriving. Sea King starts to tell Saitama that he, as the ruler of mother sea, stands at the very top of the pyramid of all living organisms on Earth. Saitama, however, interrupts him and tells him to hurry up and fight. The Sea King then quickly attempts to punch Saitama, only for Saitama to punch a hole in his body and destroy most of the street. As the Sea King falls, Genos is seen smiling, and all the spectators stare on in disbelief.
Standing triumphant over the body of the Sea King, Saitama overhears the crowd of onlookers start to question the usefulness of the rest of the heroes who battled the Sea King. Not wanting the heroes' good reputation to be tarnished, Saitama remarks loudly that he got off lucky and that, if the other heroes hadn't weakened Sea King before he arrived on the scene, he wouldn't have stood a chance. To further the credibility of his ploy, Saitama plays on the rumors of his underhanded nature by stating that, because he's the one who dealt the finishing blow, he'll get all of the credit for the victory regardless of the other heroes valiant efforts. Saitama's plan proves successful and the people's faith in the heroes that participated in the battle is restored, while Saitama, on the other hand, grows more hated in the eyes of the citizens. Internally, Saitama reflects on how dull the battle with the Sea King turned out to be.
S-Class Hero ArcEdit
Sometime after the battle with Sea King, Saitama and Genos receive a box, via airdrop from the Heroes Association, containing several letters addressed to the heroes themselves. Upon opening the five letters that were addressed to him, Saitama discovers that the first three contain nothing but hateful words accusing him of cowardice and cheating. However, the fourth letter contains a simple thank you message from an anonymous sender. The fifth letter turns out to be a letter directly from the Heroes Association itself, notifying Saitama of his promotion to C-Class rank 1, and inviting him to Heroes Association HQ in Z-City.
Upon arrival at the HQ, Saitama requests to know why he was summoned to the headquarters and suspects that they called him there to reprimand him for his actions. His hosts, however, insist that the circumstances for which he was invited are quite the contrary and they congratulate him on reaching C-Class Rank 1. They then go on to inquire as to whether or not Saitama will move up to B-Class or remain in C-Class. Saitama expresses his apathy on the subject but then goes on to state that he'd rather be B-Class due to the fact that he would no longer have to report his weekly activities to the Association. He also reflects internally that he can't remain in C-Class forever, especially considering that Genos is already an S-Class.
Later on, Saitama is walking home from headquarters, examining the official document declaring him a B-Class Hero, when a delightful smell from a small oden shop draws him inside. Upon entering, Saitama orders an assorted oden and takes a seat at the counter where he is asked by another patron in the shop if he will have anything to drink with his oden. The patron then states that, if Saitama won't order a drink, then he will treat him to one. Upon observing this stranger, Saitama discovers it is none other than a bruised and battered License-less Rider. Saitama questions why License-less Rider would want to buy him a drink, to which License-less Rider states that, if for nothing else, it would be to celebrate Saitama's promotion to B-Class and also reveals himself to be the sender of the "Thank You" letter that Saitama received. Upon finally recognizing License-less Rider as the man he saved from the Sea King, Saitama accepts his offer and orders a mozuku. Some time would pass before Saitama would rank up from 101 to 63.
Some time later, Saitama and Genos are watching as Silver Fang demonstrates one of his techniques to the duo. Upon being asked to attempt the technique, the pair express their disinterest in a non-destructive technique, eliciting an outburst from one of Silver Fang's disciples. After being questioned on the whereabouts of the rest of his students, Silver Fang explains that a long time ago one of his students went out of control and defeated a good handful of the others causing most of them to leave the dojo; subsequently forcing Silver Fang to take it upon himself to take him down. After hearing this story, Saitama remarks that Silver Fang must be quite strong evoking yet another outburst from Silver Fang's student.
Shortly thereafter, a member of the Heroes Association arrives and declares that all S-Class heroes are to report to HQ immediately to address a major crisis. Genos states that, since all S-Class are being convened, they might have need of Saitama's power and Saitama accompanies them to HQ where all but two of the S-Class have already arrived. The first S-Class hero to interact with Saitama is S-Class rank 4 Atomic Samurai who, even after hearing the praise of Saitama from Silver Fang, refuses to shake Saitama's hand; stating that he will only acknowledge those in the S-Class category. Saitama then hears a flurry of disapproving remarks at his presence at the meeting and looks over to discover the culprit is a very young girl who, to his surprise, happens to be the S-Class Rank 2 Tornado.
Saitama is the titular One Punch Man - by far the strongest character in the series. No enemy has so far been able to injure him in any way, or to survive even one of his punches. Saitama's 'power' is that his body is far beyond human limits, allowing him to achieve astounding physical feats. His strength is so great that it vastly eclipses even artificial beings designed or bred specifically for superhuman combat, such as the cyborg Genos or the warriors of the House of Evolution. Notably, since no enemies have yet posed any challenge to Saitama, the upper bound of his strength is likely even higher than it appears. However, his power is notably limited to heightened human traits; Saitama cannot fly or fire energy blasts, for example.
The origin of Saitama's unbelievable strength is mysterious and unclear. Although he tells everyone he got his incredible power through mere strength training, no one believes him. According to Saitama, after a year and half of 100 daily push-ups, sit-ups, and squats, plus ten kilometers daily running, he had achieved some level of superhuman strength. This training was apparently so intense for Saitama that he at times felt as if he might die, and claims it is what caused all of his hair to suddenly and prematurely fall out. He apparently continued training for another year and 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 to it by sparring with and observing him.
Inhuman Strength: Saitama is capable of effortlessly defeating any enemy, even ones many times his size, with a single, nonchalant punch (although this strength is not limited to punches). Saitama's punch is so powerful that many enemies simply explode when struck by it. He has also been known to effortlessly destroy walls and buildings with his attacks. An example of this casual, yet overwhelming offensive power occurs when Saitama inelegantly 'swats' Mosquito Girl through a nearby building and into the sky, killing her. His dialogue implicitly likens the attack to swatting an insect. His jaw is powerful enough to bite through and shatter Sonic's sword.
- Super Leap: His inability to fly is somewhat compensated for by his ability to use his strength to leap tremendous heights and distances. This can be shown by him smashing his head through the ceiling of a gymnasium during the hero tryouts. He was also able to crush a building, that he was on top of, just by leaping.
Extreme Speed: Saitama was able to complete a 1500 meter dash in an instant during his hero tryouts. He has proven able to effortlessly keep up with Sonic, whose main ability is super speed. Even Genos' computerized targeting systems have difficulty tracking him.
- Afterimages: He is so fast that he leaves afterimages when moving at high speeds, and is agile enough to dodge Beast King's rapid-fire Limb cutter attacks while moving in for the kill.
Invulnerability: Saitama can withstand blows from extremely powerful beings such as Asura Rhino without taking a scratch or apparently feeling any pain. Indeed Saitama has only been seen to bleed from a blow during a dream in which he imagined facing opponents close to his level. When Genos created a huge, spherical blast of flame to kill Mosquito Girl's mosquitoes with Saitama standing right next to him, Saitama was totally unharmed and unperturbed, although his civilian clothes were incinerated. It is worth noting that mosquitoes seem to be able to penetrate his skin, and that Saitama seems to prefer to dodge or block attacks using edged weapons rather than take them head on, as he sometimes does with strikes from fists or blunt objects.
- (To Beefcake) "Having an overwhelming power is boring as hell."
- (To Genos) "If the Heroes run and hide, who will stay and fight?"
- (To Genos & Asura Rhino)"The true power of us human beings is that we can change ourselves on our own"
|The Heroes Association|
|S-Class||1. Blast • 2. Tornado • 3. Bang • 4. Atomic Samurai • 5. Child Emperor • 6. Metal Knight • 7. King • 8. Zombieman • 9. Engine Knight • 10. Pig God • 11. Superalloy Darkshine •12. Watchdog-man • 13. Lightspeed Flash • 14. Tanktop Master • 15. Metal Bat • 16. Genos • 17. Pri-Pri-Prisoner|
|A-Class||1. Sweet Mask • 2. Iaian • 11. Stinger • 20. Lightning Max • 29. Golden Ball • 33. Spring Mustache • 38. Sneck • Heavy Kong • Lightning Genji|
|B-Class||1. Miss Blizzard (The Blizzard Group) • 61. Darkness Blade • 63. Saitama • Tanktop Black Hole • Mushroom • Jet Nice Guy|
|C-Class||1. License-less Rider • 6. Tanktop Tiger • 140. Red Muffler • 299. Grad School Graduate • Horse-Bone • All Back-Man • Buzz-Buzz Man • Red Nose|