Saitama/Relationships

At the start of the series, Saitama spent most of his time being a hero alone, but after meeting Genos and joining the Hero Association, he gradually gained numerous acquaintances and rivals.

Genos
Saitama met Genos after the latter was defeated by a monster and tried to self-destruct, but was instead saved by Saitama. After being saved, Genos asked Saitama to take him on as a disciple, to which Saitama nonchalantly accepts, thinking that Genos was not being serious. Though Saitama was initially annoyed by the thought of having an apprentice, he gradually warmed up to Genos, even becoming slightly worried and concerned when he saw Genos' limp body after he was defeated by the Sea King. Saitama holds some respect for Genos since he became an S-Class Hero right off the bat, and desires to move up the ranks due to his S-Class status. Genos has become Saitama's companion and friend (or at least close to it). He is also the person who he spends most of his time with, since Genos moved into Saitama's apartment to live with him. Although Saitama has yet to officially call him his disciple (as Genos is always the one identifying himself as his disciple), Saitama actually tries to train him, but since Saitama only knows strength training (which wouldn't help Genos, due to him being a cyborg), most of Saitama's advices/lessons are made up and only an excuse to keep the cyborg occupied. Despite this however, Saitama does manage to give Genos some relatively good advice from time to time. Saitama also shows some concern whenever he sees Genos in a rough state, asking him if he was still alive after seeing him defeated by the Deep Sea King and even got shocked when he was smashed into a rock by Tatsumaki. Saitama also seems to have enough confidence in Genos to handle certain threats alone, as seen when he accepted Genos' request to fight G4 alone without any pressure (although he asked him if he needs help) and would only help/save Genos, when he sees him in need.

Bang
Saitama first met Bang when the giant meteor was falling towards Z-City. Bang was amazed by Saitama's strength and wanted to keep a close eye on Saitama. He then started to spy on Saitama and was greatly surprised to find out that he was actually Genos' teacher. He than started to think that Saitama himself must have an incredible teacher but when he asked Saitama about it, he was again surprised to hear that Saitama doesn't have teacher and destroyed the meteor with his strength instead of using a technic. Bang, realizing Saitama's potential,  had since then tried numerous times to recruit him into his dojo, albeit unsuccessfully. Bang will occasionally invite him to cookouts and vice versa. Bang also showed great displeasure when Tanktop Tiger and Tanktop Black Hole were trying to drag Saitama into their "nubbie crushing", but didn't interfered since he had faith in him and even declared him to be strongest person he has ever met, showing a great amount of respect for the C-class hero. Saitama, while not seeing Bang as a friend and showing disinterest to his Martial Arts, was still slightly impressed by Bang's abilities from time to time, with the best examples being when Bang defeated him in rock, paper, scissors, and later again when Bang told him how he kicked out Garou after his rampage in his dojo, even admitting that Bang must be "kinda strong". Saitama seemed to have some faith in Bang as he called Bang to assist him in a competition against Fubuki and her Blizzard Gang. After receiving his hero name "Bald Cape", Saitama showed extreme dislike toward it and even compared his hero name to Bang's, expressing jealousy of how cool Bang's hero name "Silver Fang" sounded.

King
They first met, when Saitama saved him from Octopus Clawman during his first one-and-a-half-year of training. While Saitama seemingly forgot about their meeting, King never did and was wondering a long time who his mysterious savior was. Saitama would (unknowingly) continue to save King from various monsters, thus prompting King to (unintentionally) take the credit for killing at least five mysterious beings that were actually killed by Saitama. This caused King to gain the fame and 'fortune' as an S-Class Hero. At their second meeting, after saving him from the Giant Crow, Saitama eventually discovered King's true personality and the secret to his success. King expressed guilt for taking credit for Saitama's actions though Saitama was not upset or angry at King's secret, much to King's surprise and they even started some sort of friendship. Saitama would go to King's house to play video games, and regularly gets frustrated at losing to King. Alongside Mumen Rider and (potentially) Genos, King is probably one of the few people whom Saitama considers a genuine friend. When Garou tried to attack King, Saitama would stop the hero hunter with a single kick, saving King again.

King and Saitama also worked together to defeat Elder Centipede, with King luring it towards Saitama so that he could destroy the monster.

'The following section contains Webcomic spoilers. You have been warned manga-only readers.'

Flashy Flash
Flash and Saitama had a brief scuffle after Flash mistook him for a monster. After clearing the misunderstanding, the two became acquainted with one another, with Flash acknowledging Saitama's superior abilities.

After being defeated by Garou, Flash was one of the few who regained consciousness and was able to witness Saitama defeating Garou. In addition to acknowledging Saitama's strength, Flash has decided that he wants to teach Saitama some proper fighting techniques.

Fubuki
At their first encounter Fubuki tried to force him into joining her group, as was fearing about her rank. After witnessing how powerful he was when she fought him in his apartment, how he fended off Sonic and that he had friends in S-class, she started to admire him and decided to join him. She was sometimes seen along with King and Genos hanging out in Saitama’s abode. She is apparently obsessed with making Saitama join the Blizzard Group, with her latest attempt was to beat Saitama in a video game competition, which failed due to King’s assistance. Despite knowing that Saitama was superior in terms of power she still doubted that he could actually surpass Sweet Mask and her sister. Fubuki also often becomes irritated by his behavior like when he wasn't listening to her deal and later ditched her with the bill to chase after Garou, which greatly irritated her. Despite this however she was still ready to bring him the cabbage he left at the restaurant and was ready to forget about their mishap if he apologized to her. Fubuki also shows a softer side of hers towards him and shows a lot of patience with him.

'The following section contains Webcomic spoilers. You have been warned manga-only readers.'

When Tatsumaki asked him what her Fubuki is for him, Saitama declared her to be an "acquaintance", showing that their relationship has not really progressed at all, which deeply hurt her. Despite this however, he was still ready to protect her from Tatsumaki, showing that does care for her to some degree. After witnessing Saitama defeating Garou and later going toe-to-toe with Tatsumaki, her obsession with him only grows stronger, as she vows to make him join her group at any cost and also admitted that she was wrong about him not being able to reach the top. Thanks to Saitama's assistance in the battle with her sister and her subordinates determination to become stronger, she finally became encouraged enough to join A-Class.

Zombieman
When Saitama heard of Zombieman's immortality by Genos he became interested in the S-class hero and asked him if the rumors were actually true, although Zombieman looked rather displeased by having Saitama around, due to his rank. When Dr. Genus later warned him about Saitama's strength, Zombieman refused to believe him, even thinking that the former scientist was making fun of him.

'The following section contains Webcomic spoilers. You have been warned manga-only readers.' After witnessing Saitama's fight against Garou however, he completely changed his mind about Saitama, realizing that everything Genus said about him was true. He then visited Genus again and asked him to remove his limiter as well and to make him equal to Saitama, as he started to feel inferior to the B-Class Hero. Zombieman was shocked, when Genus told him that he can't do so, but the scientist still decided to help him, by showing him something "interesting" in his basement.

Tatsumaki
In their first encounter, Tatsumaki didn't think much of Saitama due to his ranking, and would regularly insult him. She feels insulted whenever Saitama ignores her. Saitama once mistook Tatsumaki for a little girl due to her small stature, and found her to be annoying.

'The following section contains Webcomic spoilers. You have been warned manga-only readers.'

Their next encounter would be when they 'fought' in the Psychic Sisters Arc, which is when Tatsumaki discovers Saitama's true power. Saitama displayed concern and interest toward Tatsumaki, as he ran after her to see if she would be alright flying home with her injuries, and was interested in why Tatsumaki pushes everyone away. However, Tatsumaki simply yelled at him, causing him to be even more irritated at her behavior. Tatsumaki came close to revealing her past with Blast to Saitama before deciding not to.

Despite her dislike towards the A-class hero, she still came to acknowledge his strength, even asking him about his name and when she trapped him underground she still admitted that this probably won't kill him. After their fight she admitted that he was "kinda strong", showing that her mind about him was slowly increasing, although she still believed that she would've beaten him in five seconds at here full strength and also called him an "asshole" for hiding his true strength and for holding back during their battle, much to Saitama's annoyance.

In an audiobook, it is revealed that the two actually met in a haunted house at a festival Saitama worked at. Saitama thought Tatsumaki was a lost child, and Tatsumaki called him a balding samurai and thought he was a ghost when her powers didn't work on him.

Mumen Rider
Saitama and Mumen Rider share a mutual respect for one another, and a possible friendship.

Saitama respects and acknowledges Mumen Rider's ability to continuously meet the weekly quotas of the C-Class heroes, something Saitama found to be a difficult job. He also compliments Mumen Rider for putting up a nice fight against the Sea King. Mumen Rider is one of the few who knows of Saitama's true strength, and treats him respectfully as a fellow hero. He sent Saitama a thank-you letter for defeating the Sea King and offered to treat him to dinner, where he personally thanked Saitama, further showing Mumen Rider's humble and respectful nature.

In an extra chapter, it is revealed that he and Saitama were once schoolmates, but neither are aware of this fact.

'The following section contains Webcomic spoilers. You have been warned manga-only readers.'

Forte
One of Saitama's new neighbors after he moved to A-City. Originally Forte thought little of Saitama, seeking to abuse his upper rank status to pressure him. When Saitama was accidentally insulting his fighting style he wanted a match with him, only to get hit by a car. After witnessing a seismic event caused by his fighting and later witnessed that the cause of it was Saitama going toe-to-toe against Tatsumaki he realizes neither he, nor his accomplices, could hold a candle to Saitama. He then decided to be accepted by Saitama and getting on his good side, apologizing for his rude behavior earlier and agreeing to take of Overgrown Rover and Black Sperm for him. He also told his accompanies that they won't stand a chance against Saitama and gave them the advice to work on being accepted by him as well.

Sneck
Originally Sneck thought little of Saitama due to his rank, as well as the fact that Saitama almost flunked the hero exam. But after he heard about Saitama breaking the exam's physical records and being swiftly defeated by the rookie, Sneck began to recognize Saitama's abilities. Saitama once unknowingly avenged Sneck when he killed the Sea King, and defended his honor when he and the other heroes who were defeated by Sea King were being insulted. Sneck was the only person in the Super Fight tournament who was able to figure out he was not Charanko (but it did take him a while).

He saved Sneck from being crushed by Bakuzan.

Sweet Mask
At first, Sweet Mask looks upon Saitama with his typical disinterest in the lower class heroes. When first hearing mention of him after Saitama killed the Sea King, Mr. Mask opinion relegates the newbie as having the aura of a B-Class hero, based on appearances via the video feed alone.

'The following section contains Webcomic spoilers. You have been warned manga-only readers.'

After witnessing Saitama defeat Garou however, not only does Sweet Mask fully acknowledge Saitama's tremendous strength, but becomes somewhat obsessed with him, considering him to possess the true beauty of overwhelming power.

Suiryu
Suiryu holds great respect for Saitama (who was under the disguise of Charanko) not only because of his strength and humble personality, but also for the fact that they share the same dilemma in finding worthy opponents to fight. Suiryu also admits that Saitama is the only person worthy enough for him to share his disdain for the hero lifestyle, in which he keeps hidden in his sub-consciousness. After Saitama's true identity is revealed and the jury was about to disqualify Saitama because of this, Suiryu refused to win like this and started fight Saitama with  his full strength. When his attacks had no effect on Saitama he started to fear that he could may lose and started to attack Saitama with even more powerful and deadly attacks.

After being accidentally defeated by Saitama from a hip strike, he begins to fear Saitama, not wanting to bump into him again in the future.

When Bakuzan was about to kill Sneck, to torment the already beaten and desperate Suiryu even more, Saitama showed up and stopped the monster, thus causing Suiryu to tearfully cry upon seeing a hero come to his rescue. He was impressed to see Saitama easily killing Bakuzan with one punch, but still doubted that Saitama could take on Gouketsu and warned Saitama for the monsters strength. However all his attempts to stop the hero were in vain, thus causing Suiryu to angrily slam the ground and to lament that the only hero he started to respect has just walked into his death. After Saitama send Gouketsu's head flying back to the stadium right before a shocked Suiryu, not only does Suiryu come to acknowledge Saitama's god-like power, but also becomes very grateful towards Saitama for saving his life and goes as far to ask Saitama if he can become become his apprentice (like Genos), only for him to decline. Furthermore, after witnessing Saitama's heroic deeds, he now aspires to become a hero himself and asks Saitama if he can become one, to which he replied that he can.

Speed-o'-Sound Sonic
Speed-o'-Sound Sonic views Saitama as his eternal rival and vows to defeat him. Saitama views their one-sided rivalry relationship in a nonchalant manner. He does not mind Sonic's persistence and their continuous 'battles', even going so far as to encourage Sonic to do his best. However, he does grow irritated if Sonic starts to bother him during important activities, or causes havoc around others.

According to Genos, Sonic is one of the few people who recognizes Saitama's true strength. This recognition is what caused Sonic to stop working and continue training in order to surpass Saitama. This recognition and dedication, as well as declaring Saitama a rival and admitting defeat at his hands, indicates (in his own way) a form of respect that Sonic has for Saitama.

Dr. Genus
After witnessing the destruction of several of his creations, Genus began to study Saitama. He theorized that at some point during his training, Saitama broke through a natural limiter that humans have, but having paid the price with his hair and his emotions.

It is also shown that Genus holds a great deal of respect for Saitama due to his efforts to successfully remove his limiter to attain godly power, defining all of Genus' ideology about artificial evolution to create better and stronger beings, as well as his desire for eternal life. Furthermore, he respectfully appreciates the fact that Saitama shows him that human willpower alone is able to lift one to incredible heights.

Boros
While being disgusted of Boros destroying other planets during his search of an worthy opponent and getting annoyed by his life story, Saitama still sympathizes with Boros for not being able to find a worthy enough opponent that could give him a stimulating fight, thus prompting him to hold back during their fight to give them both an equal and satisfying duel. After being kicked to the moon by the alien and returning to the earth however, Saitama isn't holding back anymore and attacks Boros with more force, which he only survives thanks to his strong regeneration abilities. Boros is also the first opponent that Saitama had to use a serious attack against in order to defeat it. While Boros in his last moments admits that Saitama is far stronger than him and realizes that he wasn't even nearly using his actual power, Saitama has respect for Boros and deems him to be the strongest opponent he has ever faced so far.

Choze
Choze formed a grudge against Saitama after the latter defeated him in a match while yawning. In his monster form, Choze believed that he could defeat Saitama. Ultimately, Choze would never get his chance for revenge, as he was defeated by Suiryu soon afterwards.

Garou
Saitama first encountered Garou while shopping for a wig, and easily defeats him. He then defeats Garou again with a single kick. He defeated Garou a third time after he dined-and-dashed.

'The following section contains Webcomic spoilers. You have been warned manga-only readers.' Garou displayed hatred toward Saitama during their fight, viewing Saitama as the personification of the collective unfairness of the world. Adding to that, Saitama is a hero, and represented everything that Garou hated and was fighting against. Saitama is responsible for defeating Garou both physically and mentally, realizing that Garou wanted to be a hero instead of a villain.

Saitama showed mercy towards Garou, refusing to kill him and acknowledging his flaws.