Saitama lives in a small apartment as a seemingly average man with a bold personality. Saitama aspires to be a hero and loves the thrill of a challenge, but there's just one problem: Saitama is so much stronger than his opponents that they go down after a single punch. Whether that opponent is a 100+ meter tall giant who has destroyed multiple cities or an evil sea king determined to exterminate the entire human race, one punch is all it took for them to be taken down. As the name of the series suggests, Saitama is the One Punch- Man.
Saitama is the main protagonist in the series One Punch Man, created by a Japanese web comic designer under the pseudonym ONE. One Punch Man originally appeared on ONE's website on June 3rd, 2009.
Later, after the series had gained much success, mangaka Yusuke Murata approached ONE about a collaboration and they made an upgraded remake manga format of One Punch Man appearing in Shueisha's Young Jump Web Comics on June 14th, 2012. The story remains the same, but Saitama and his art are significantly upgraded. Murata has also made several extra chapters and added onto events of the original story.
Saitama was originally a lazy man looking for a job after repeated firings until one day he encountered and saved a young boy from a monstrous crab and was inspired to become a hero. From that day on, Saitama participated in an inhuman workout consisting of 100 push ups, 100 sit ups, 100 squats, and 10km of running every day which somehow led to his amazing powers, but as a side effect he lost his hair.
Saitama is a young, average looking male who is completely bald. Despite being short and thin, he is incredibly lean and muscular and has a perfect body. Saitama is usually drawn in a goofy, simple manner but at more serious moments in the series his true features are shown. It is revealed he has sharp, well-toned, and angular features. He has beady black eyes and formally spiky black hair
The series starts with an alien who crash lands into a city by a massive explosion, and proceeding to wreak havoc through multiple energy blasts. Saitama is watching about it on a television. He then arrives just in time to save a little girl before she is crushed by the giant alien.
The giant, curious, asks who Saitama is. The giant introduces himself to be Vaccine Man, someone born out of pollution caused by ""filthy humans" as he put it. He deems humanity a virus on mother Earth and expresses his intent to destroy humans, calling himself the apostle of mother nature.
The Giant transforms into a monster dwarfing Saitama, with claws on his hands the size of entire cars, with elephant like tusks and spikes all over its back. Without giving much thought to the giants lecture, Saitama punched the monster around its belly, exploding the monster from the middle. After realizing what had happened, Saitama grows frustrated and start yelling. Another fight for him, that had ended with a single punch.
A while after that encounter, Saitama runs into the Brain and Brawn brothers who were destroying D-City, and he leaps onto Marugori's shoulders. Marugori's brother, who notices Saitama, then order's Marugori to swat Saitama, but Marugori instead accidentally kills his own brother. In a massive rage, he then throws Saitama down and proceeds to rush him with a barrage of punches, which causes widespread devastation to the surrounding area and makes a huge crater. Saitama, unaffected, leaps from the crater and delivers a mighty blow to Marugori's cheeck so powerful it warps his face and kills the giant instantly.
He then has a dream that he is fighting the Subterranean race, who have killed a majority of population and destroyed Saitama's apartment. He then fights them with energy and vigor, but wakes up as he is about to face Subterranean King.
House of Evolution Arc:
Saitama is going through an existential crisis, regretting the state his life is in and how all of his battles end too easy because of his overwhelming strength. He compares all of his fights to swatting insects. Just then as he is watering his plants he swats at a mosquito, who miraculously survives. He then engages in a comedic battle with the mosquito, who is shown to fly off to Mosquito Girl. At the same time, Mosquito Girl attacks the city and is confronted by Genos, who begins to fight her. Saitama, pursuing the mosquito, runs into Genos and Mosquito Girl. Mosquito Girl then absorbs all the stored blood from her mosquito's and powers up. With her newfound strength and speed she quickly tears Genos apart, who decides the only way to defeat her is to self-destruct. Saitama then steps in and slaps Mosquito Girl, killing her instantly. Genos, shocked, asks Saitama to become his master.
Powers and Abilities
Saitama is the most powerful character, as well as the true top tier of One-Punch Man. His physical parameters are so incomprehensibly large that all of his battles are borderline gags, due to him defeating every enemy is a single punch. Not only this, he has never been injured thus far in the series, nor has he ever lost a battle of even come close to trying in one. Due to all these factors it is incredibly difficult to grasp Saitama's true power, since he hasn't displayed a portion of it so far.
Immeasurable Strength: Saitama's strength is limitless, The author of the manga "One Punch Man" himself said that their is no limit to his strength. The things Saitama hit tend to explode with the force of the impact. Saitama's strength caused a building to collapse when he leaped up from it. The upper bound of Saitama's strength has never been measured, as he has not fought an opponent strong enough to test his powers with. Almost all of his opponents were at least city+ when it came to destructive capabilities, but Saitama has easily ended most their lives with a single punch. He destroyed a city-wiping meteor with a single punch, completely unscathed. Saitama's Super Move "Series" Serious Strike was a punch that had so much air pressure that it split a planet-destroying energy attack in half and caused the clouds in its direction to disperse on a global level, and it is later revealed that Saitama was not actually serious with the punch. Needless to say, his superhuman strength allows him to lift/carry/throw hundreds of tons effortlessly.
Immeasurable Speed: When it comes to speed, Saitama easily surpasses Speed of Sound Sonic, a powerful villain who transcends the speed of sound and further into the series he blocks and dodges attacks from Lightspeed Flash, an S ranked hero who claims to transcend light speed. Saitama also easily out-speeds people who have made Sonic and Lightspeed Flash seem slow. Another of Saitama's "Series" was Serious Consecutive Side Hops, by hopping side to side rapidly he was shown to create hundreds of afterimages and is able to walk forward while doing so. Another feat of speed he sports is when he jumped from the moon to the earth in nine seconds after the alien king Boros punted him to the moon. To put that into perspective, he has the jumping power to go anywhere around the earth and travel 13% the speed of light. During his "hero registration test," Saitama ran a casual 5 second mile, which would put his effortless, running speed just over 700mph. Obviously, Saitama can achieve speeds several times the speed of sound without any significant strain or effort.
Immeasurable Agility: Saitama possesses an extraordinary agility and can perform many acrobatic and athletic maneuvers with proficiency, he can also dodge attacks from enemies far faster than light speed like Speed-O-Sonic and Flashy Flash with little difficult.
Saitama is also extraordinarily flexible and can pass even through the most narrow and tight places, which makes his dodging ability even higher.
Extraodinary Senses and Reflexes: Saitama is able to hear, see and smell far beyond than normal humans can, he can easily follow an object or person even if it goes at light speed without losing focus on it. He can easily read, dodge and counter attacks and techniques from any enemy no matter how powerful, fast or skilled may be. He can also hear conversations from people miles away from where he is, he can also feel whenever someone's watching or spying him and can even predict when someone is in danger or something bad is happening.
Invulnerability: None of his opponents have been able to so much as put a scratch on him, in part due to the fact that they don't get the chance to. But even when Saitama gave one of his opponents the chance to fight back, Saitama took a punch of someone thrice his size and immensely strong like it was nothing. There wasn't so much as a single scratch on his face. Saitama has taken a kick that sent him to the moon seemingly instantaneously without any harm done. In this same scene, he withstood the pressure of space without any issue. Not even the gravity of an black hole has possessed a challenge for him.
Enhanced Jump: Because Saitama doesn't have an ability like flying or teleportation, he mostly uses his strength to leap great distances to wherever he needs to go. His greatest leap to date was him seemingly casually jumping from the Moon back to Earth in what seems to be seconds. Saitama is also able to jump in the air, as seen in his sparring with Genos, where they briefly fight in the air and Saitama has no problem following him via jumping.
Psychic Resistance: Saitama was able to resist being affected by Tatsumaki's telekinesis, and this has been attributed to his immense will power. It should be noted that Tatsumaki is the most powerful esper in the series, and has been shown to be able to effortlessly call meteors from outer space, and restrain characters as powerful as Garou.
When Geryuganshoop (Boros' right hand) created an gravity environment that according to him, was equivalent to a black hole, Saitama didn't show the slightest sign of annoyance and could walk as nothing was happening.
Temperature Immunity: Saitama has shown to be invulnerable to any attack based on temperature or even temperature in general, as fire attacks do seemingly nothing harmful to him. In the opening of the anime, he is seen walking peacefully on an place where is snowing and shows no sings of cold whatsoever.
Master Hand-to-Hand Combatant: Despite having no formal training, Saitama's experience fighting monsters and criminals along his superhuman physical trait has made him an extraordinary powerful and skilled fighter. While normally relying on raw power to win, he has proven to be far more skilled and smart than he appears, he can easily read the moves and techniques from enemies far more trained and experienced than him, and can skillfully combine his physical prowess to overwhelm his opponents. Saitama's fighting style is mostly improvised, with basic fighting techniques, but efficient and practical, he is able to strike, counter and attack with great precision and finesse when serious, and has mastery over his overwhelming abilities and knows how to use them efficiently in combat. Saitama also uses karate chops and some grappling moves.
Supernatural Accuracy: Saitama always hits his target without failing, he rarely fails a hit when he punches someone, he is shown to be very good at hitting even with objects, as he could hit and kill Geryuganshoop with a rock without even taking the time to aim. He was able to jump from the moon to earth and land in the same place where Boros threw him out of earth with no problem, later revealing this to be his intention from the beggining as he managed to destroy Boros' ship this way.
Mosquitoes: As a gag, Saitama had serious troubles tagging a mosquito that was pestering him even though he can react and move at near light speeds.
Martial Arts: While a skilled and experienced fighter in his own, Saitama has no skill whatsoever in martial arts, so he can be surprised or outsmarted by enemies skilled in that kind of fighting styles, like Garou or Bang.