Genos/Synopsis

Early Life
At age 15, Genos was still a human being living a happy and peaceful life along with his family. One day, a crazy cyborg attacked their town and destroyed it, killing his family. Genos miraculously survived, but he wouldn't survive long alone in his ruined town if he wasn't found by Dr. Kuseno who passed the town pursuing the cyborg. Genos begged Dr. Kuseno to transform him into a cyborg, who complied. Genos was reborn as a cyborg fighting for justice and promised Dr. Kuseno that one day he would find and destroy the cyborg.

For the next four years, Genos traveled from town to town defeating monsters and evil organizations, but was unable to find the whereabouts of the cyborg.

House of Evolution Arc
While Mosquito Girl is in the middle of her rampage in Z-City, she notices that quite a few of her mosquitoes have died and looking down, she spots a form swarmed by mosquitoes. She sends more bugs at the form, but they are all blasted away, revealing Genos. He has a stern expression on his face and declares that he will eliminate Mosquito Girl. Genos then fires a blast at her, but she easily dodges his attack and dives at him, taking his arm in the process, but in return he takes out both her legs below the knees. Mosquito Girl then flies away and summons all of her mosquitoes to give her their blood. Genos says that her efforts are useless, but is concerned when he sees the amount of bugs gathering around her. As he is about to charge his laser, Saitama comes running out on the street. Genos warns the so-called civilian, but Mosquito Girl's swarm of mosquitoes comes crashing down on them in an instant. Genos releases his heat beam and burns all the bugs, while telling his foe that making them attack in one big chunk makes it far more easier to destroy them. He realizes that Saitama was still in the area, but is shocked to see that he is fine, with only his clothes burned.

Mosquito Girl, now evolved, rushes down and appears behind Genos, cutting him almost completely in half. Genos then spins around to attack her but she dodges and begins to attack him continuously to the point that he was about to blow himself up to kill her as a last resort. Before that can happen, Saitama ungracefully smacks Mosquito Girl in the face, sending her crashing through a building and into the distance, killing her. Genos, greatly surprised by this, asks Saitama his name and for Genos to become Saitama's disciple.

A week later, Genos shows up at Saitama's apartment, having been fully rebuilt, to discuss being Saitama's student. Genos rather long windily begins to tell Saitama about his past, but Saitama tells him to come back when he can sum his story up with a max of ten words. Sometime after, Genos simply asks Saitama to teach him to become strong like him. Saitama warns Genos that it's going to be tough and agrees to train him. But at that moment, Genos turns, saying that he senses a presence moving at high speeds towards them when Kamakyuri smashes through the roof, only to be swiftly killed by Saitama. Genos and Saitama leave the building to find Frog Man and Slugerous on guard. Genos tells his master that he will take care of them, but before he can finish his sentence, Saitama has already smashed both creatures head first into the ground. Then, Saitama unexpectedly gets dragged down underground until only his head is showing. Genos starts to rush to Saitama's aid, but Armored Gorilla suddenly bursts through the wall behind them.

Armored Gorilla then attacks Genos who easily stops the attack. He says that he needs to ask the creature some questions. He then notices Beast King approaching Saitama, who is still buried and goes to help him but gets grabbed by Armored Gorilla who he then blasts away, and starts to run to Saitama again. Armored Gorilla attacks again and Genos is forced to jump away. The cyborg reveals that he is affiliated to the House of Evolution. Genos recognizes the name and asks what they want of his teacher. Armored Gorilla doesn't reply and simply states the he must destroy Genos. Saitama is then shown taking out Beast King and Ground Dragon and approaching Genos who is standing on an incapacitated Armored Gorilla, having defeated him in an off-screen fight. After showing Armored Gorilla that Saitama has killed Beast King, he agrees to tell them whatever they wanted to know.

Armored Gorilla reveals the history of Dr. Genus and the House of Evolution. He summarizes that the doctor has taken interest in Saitama's body and Genus clarifies that he wants to use Saitama's god-like physique to build the new human. As they take off to the House of Evolution's base, Genos asks some last questions. He asks about the House's involvement with cyborgs and Armored Gorilla replies that he's the only cyborg of the organization. Genos is disappointed. Four hours later, Genos and Saitama have arrived at the House of Evolution's base. When they find it, Genos promptly destroys the building and part of a mountain in the distance. Saitama is surprised of Genos' quick actions and notices a hatch on the floor and rips it open before Genos and him head down into the lair.

As they're walking down the hallway, Genos notices several life forms, two of which are coming at them at high speed. Carnage Kabuto appears, carrying Dr. Genus, who then points out Saitama, identifying him as Carnage Kabuto's target. Carnage Kabuto then throws Dr. Genus to the side and smashes Genos against the wall. The creature challenges Saitama to a fight, and he agrees on the grounds that Carnage Kabuto made Genos look like "modern art." Carnage Kabuto then shows Saitama to a rather large room and they are about to fight, but Genos suddenly appears and blasts Carnage Kabuto. Genos then rushes at Carnage Kabuto and hits him with a barrage of punches, but it doesn't affect the monster and he smashes Genos in the face, throwing him into the ground and causing his face to crack and his left eye to fall out. Saitama catches him and says he'll handle the fight, but Genos, stubborn as he is, sends a devastating blast at Carnage Kabuto. However, the opponent uses his breath to blow the attack back and blasts Genos instead, causing Genos' hair to puff up into an afro.

Saitama gets serious and proceed to challenge Carnage Kabuto, but the latter stops his assault when he detects Saitama's abnormally high strength and questions Saitama about the source of that strength. Saitama decides to reveal the secret to his power and Genos is amazed and is eager to finally know, but inwardly questions whether it is wise to divulge the secret to his enemies. Saitama explains that it is simply the result of hard work and training and obviously, Genos doesn't buy it and is skeptical. He tries to persuade Saitama to let him know the real secret, but Saitama simply replies that it's just that. Carnage Kabuto goes berserk and pummels Saitama, but he unexpectedly delivers but one punch to the monster and destroys him. Genos and Saitama return home after this.

In the anime, officers of the Hero Association find the results of Genos' blast that destroyed the top eight floors of the House of Evolution and identify Genos as the perpetrator of that blast.

Paradise Group Arc
Genos only appears briefly at the end of the arc, when he reveals to Saitama that he is not famous because he never registered himself with the Hero Association. He tells the history of the Association to Saitama and they agree in getting them both registered.

National Superhero Registry Arc
Genos and Saitama sign up at the 6th official superhero certification exam center. After he finishes the physical and written exam, he is greeted by Saitama in the changing rooms. They agree on how both tests were super easy and that they'll probably get full points too. A hour later, they receive their scores, revealing that Genos received a perfect 100 and is certified as a S-Class hero, though he wonders what that is. Genos becomes enraged when he hears that his teacher scored 71 points ranking him as a C-Class. They are then told to go to a lecture hall for a seminar of the successful candidates.

As they arrive in hall 6, they are congratulated by A-Class Superhero Snek. He gives them some advice on being a hero and the rankings, though Genos isn't interested in it. As they leave the seminar, Genos is glad that he finally becomes a real disciple of Saitama and counts on his guidance, though Saitama isn't actually glad with it, and they part ways soon after.

The next day, Genos and Saitama appear around a mountain area, with Genos sporting new black mechanical arms. Genos checks his phone, stating they are at the last place of their respective classes and that they didn't receive hero names yet. He puts the matter aside and thanks Saitama for accepting his "unreasonable request". The two prepare for battle, though Saitama believes it to be a sparring match, however Genos will attack with everything he's got. Genos positions in a battle stance and aims his left arm at Saitama, ports of his arm opens revealing several cannons.

He fires a single massive beam at Saitama. As it reaches Saitama, he dodges it, however Genos immediately retaliates by dashing towards Saitama. He takes a hold of Saitama and crashes him to the mountain, punching several times across the wall of the mountain, but he soon realizes that he was attacking Saitama's after-image. Genos immediately detects that Saitama is running away and intercepts him by landing in front of him and firing a massive beam. Genos believes he hit and defeated Saitama, only to have Saitama poke him in the cheek from behind and proclaiming victory.

Genos becomes angry and attacks him, but Saitama jumps away unscathed. Genos then reminds Saitama the rules of the fight, one of which is to continue fighting until he is unable to. They continue the fight, in hoping that he will discover insights of Saitama's power, however Saitama shows impressive fighting prowess and lunges to punch Genos, but instead flicks him and invites Genos to eat udon. Genos watches Saitama walk away, as he is still flabbergasted of the force of the last punch, that destroyed a mountain behind him, realizing his teacher is on a whole other level.

Five days later, Genos decides that he wants to live with Saitama, which Saitama does not agree to, though he changes his mind when Genos offers to pay him rent. Genos then proceeds to write in his diary on his teachings. Genos then informs him that C-Class heroes will be excluded from the hero registry as they are not deemed worthy by the registry if they do not work. Saitama freaks out and decides to do heroic deeds. Genos wants to accompany him, but Genos is convinced by Saitama to aim towards the top ten ranking of the S-class, as Saitama believes that if Genos were to accompany him, he would inadvertently steal all the credit with his mere presence.

Rumored Monster Arc
While Saitama was cooking kombu, plucked from Kombu Infinity, Genos wonders why there is a pile of kombu outside, which Saitama tells him it was cheaper. Genos asks Saitama if he thought that kombu would let him regrow his hair, that it will actually not, as it was not proven as a genuine medicine, to which Genos receives an angry response from the infuriated Saitama.

Giant Meteor Arc
Saitama and Genos are relaxing and reading the newspaper. Genos states that Saitama went up in the C-Class ranking from 388 rank to 342 and that while he is still last in the S-Class ranking, in popularity he is ranked 6th, by public votes, shocking Saitama. Then, he mentions several comments about him, but is not impressed since they are all only based from one single picture of him. Even though the world does not acknowledge it, he is still astounded by Saitama, which creeps him out.

Genos receives a call to go to the Hero Association for unknown reasons. When he arrives at Z-City branch, with a suitcase, he is greeted by the third-ranked S-Class superhero Bang, who reveals that the Hero Association ordered a mass evacuation and that he and Genos are the only S-Class heroes who showed up to prevent the disaster. He explains that they were given an impossible task: a Dragon-Class Disaster is coming to Z-City in the form of a giant meteor. Genos is advised by Bang to evacuate before the meteor impacts. Genos wonders what Bang is going to do, which he replies that he decided to protect his dojo, but as he turns around to show his fighting style, Genos already left.

Genos is later shown to be leaping from rooftops, observing the panic and prepares himself for an attempt to stop the meteor. Genos activated his "Arms Mode" suitcase and throws it in the air, forming it into a pair of arms and attaches to himself, surging electricity through his body. As he decides to destroy meteor in order to protect his teacher, a large, humanoid, unmanned drone flies above him towards the point of arrival of the meteor.

Genos reveals the large robot to be another S-Class hero called Bofoi, and asks for his help in stopping the meteor. Bofoi refuses and states that he is only there to test a new weapons system. He also advises Genos to call fellow heroes by their nicknames in professional situations, and stating that his is Metal Knight. The meteor looms closer so Genos runs off to a different roof and prepares himself to attack the meteor. Before he can do anything though, Bofoi lets off a massive volley of missiles, which in the end do nothing to stop or slow down the meteor. Genos starts to prepare, but starts to doubt his abilities when Bang shows up and calms him down. Genos thinks of Saitama and comes back to his senses. He opens up his chest to reveal his power core which he attaches directly into the shoulder of his left arm. He tells Bang to get down and then launches a massive attack at the meteor. His attack does nothing to the meteor unfortunately and Genos runs out of power and collapses on the roof. Saitama shows up and destroys the meteor, causing pieces of it to rain on the city. Bang carries Genos to safety.

Genos makes a brief appearance at the end of the arc in his and Saitama's apartment, regretting his inability to stop the meteor. After a short discussion he reveals that his rank has been increased from 17 to 16, Bofoy's from 7 to 6 and that Saitama has been raised from rank 342 of the C-Class to rank 5 of the C-Class. He also explained the Disaster Level System.

Sea Monster Arc
Genos makes a appearance at the beginning of the arc in their apartment discussing Saitama's ranking after he killed a Seafolk from the other day. When he was about to explain the top B-Class hero, he gets a call that J-City is under attack and there was no competent heroes nearby to help. He and Saitama head out despite it being far away from where they are residing. On his way, he met a naked Sonic who had just escaped from the Sea King. He was the first to arrive in the Evacuation Shelter where the Sea King just took down four heroes. He put up a fight and traded blows until he was hit by the Sea King's Acid to save a girl, which ultimately disabled him. However, Saitama arrives and easily defeats the Sea King with a single punch. In the aftermath, the people were thankful but one criticized heroes for being defeated by the villains and the monster, despite their efforts. Annoyed by this, Saitama pretended to take all the credit by himself, with the purpose of giving credit to those who gave their all. Realizing this, Genos's respect towards his teacher grew more.

Alien Conquerors Arc
Genos arrives to the Hero Association meeting with Bang and Saitama; they are greeted by Atomic Samurai. He later goes to the roof of the Hero Association HQ with Child Emperor, Superalloy Darkshine, Tatsumaki, and King. There he asks Tatsumaki if he can help, only to be declined. Afterwards, Genos appears beside Child Emperor and Engine Knight and is told by Engine Knight to not trust Bofoy. Later when Bofoy's robot appears, Genos asks Bofoy what Bofoy's intentions are. Genos is relieved when he sees that Saitama is okay after the crash. However, soon Tatsumaki erupts into a fit of anger for being ignored and begins insulting Saitama. Genos retaliates by calling her a shitty brat. Unfortunately, Tatsumaki did not take that comment nicely and launches Genos at a large chunk of debris.

King Arc
Genos fought and defeated G4. Genos then went to Dr. Kuseno with the remains of G4 to get repairs. Genos tells Dr. Kuseno that he wants to become stronger. Dr. Kuseno replies that Genos's master has given Genos a very reckless goal and asks whether Genos can bring Saitama the next time Genos comes. Their conversation continues with the discussion of the cyborg that took Genos's hometown. Dr. Kuseno ask Genos whether he found any clues about the cyborg's whereabouts, which Genos replies with no. However, Genos reaffirms that he will destroy the cyborg, once he finds him. Dr. Kuseno reminds Genos that he is not alone and that the conflict with Mad Cyborg is their conflict and not just Genos's.

Lobster
After being called over to Bang's dojo, Saitama learns that Bang got a whole bunch of lobsters from his brother and needs someone to help him eat them. Genos complains about them being called out for something insignificant, and tells Bang to call someone else if he needs help eating leftovers, at which point Saitama tells him to stop, saying that they're only helping a lonely old man with his food problem. After Charanko arrives with the vegetables, they start preparing the hotpot while talking about a recent dojo hunter that has been attacking other dojo's. Saitama notices that there isn't any cabbage, interrupting the conversation about the dojo hunter, which annoys Charanko. After seeing Saitama look bummed about the fact that there isn't any cabbage, Genos angrily asks Charanko why he planned to make hotpot without cabbage. Saitama tries to say that it's fine, but Genos keeps arguing with Charanko because he does not feel like he even feels sorry for not having bought cabbage. After Charanko challenges Genos to a match, Bang tries to calm down the situation by saying that he will go buy the cabbage, and asks Charanko to get along with the other two.

The Blizzard Group Arc
Genos suddenly sensed something coming towards their place and went to check it out which is revealed to be Sonic who claims himself as Saitama's rival. Not wanting to disturb a busy Saitama, Genos decided to take him down on his own. They are on equal footing, with Sonic too fast for him but he, too durable from his attacks. As he tried to land a blow against Sonic, he accidentally caught Fubuki who is fighting Saitama in the way with it's impact. Saitama asked him what's going on and he replies with an apology for messing up the place. He suddenly recognized Fubuki and misinterpreted her position as a failed attempt of taking down Saitama. Fubuki was surprised that he, an S-Class Hero actually called himself a disciple of a B-Class Saitama. Sonic attacks him again, this time with exploding shurikens but was unharmed. Despite his loss in speed after this, he is durable enough to take all of Sonic's attacks and decided to increase his speed to catch up. Sonic barely evades this attack, but Genos manages to cut off his hair. This angers Sonic severely and he stops taking the fight light. Sonic uses Four Shadows Burial, thus preventing Genos from tracking Sonic. As a last resort Genos decides to try to blow up the general area. However Saitama knocks down Genos before the cyborg can do so. Saitama then brings the fight into his own hands. While watching Sonic fight Saitama, Genos admits that while Sonic is a buffoon, he must have worked hard to gain his abilities. Afterwards, Genos, Fubuki, and Saitama go to Saitama's home and listen to Fubuki discuss her ideology.

Hero Hunt Arc
Genos is briefly seen at the beginning of the arc talking to Charanko. He reveals that Garou has been put on the Hero Association's wanted list of vicious monsters and that Bang has volunteered to get rid of Garou. Genos later tells Saitama that his parts have changed and that his speed and power has been enhanced with the parts of G4. Furthermore, Genos tells Saitama that he has gained hair made of heat and shock proof fiber. Suddenly Genos comes to the conclusion that Saitama wants transplant hair as well. When Saitama comes back with a wig, Genos comes to believe that Saitama is very desperate and calls Dr. Kuseno to make an appointment to give Saitama a hair transplant. Saitama then explains that it is simply a disguise for the tournament and invites Genos to come to the tournament with him at C-City.

Monster Raid Arc
Genos goes to the martial arts tournament in C-City to spectate over Saitama at the tournament. He claps for Saitama during Saitama's introduction.

Upon watching the victory of Saitama against Zakos, Genos receives information about the attacks of an unknown group of monsters in the cities and targeting heroes. In addition there are monster in C-City, thus Genos has to do his hero work to eliminate the monsters while Saitama focuses on the tournament. As Genos eliminates the monster nearby stadium, he receives a call from the Hero Association about the remaining monsters in C-City. After defeating six out the seven monsters in the city, Genos is called again by the association about the location of Awakened Cockroach.

During the fight with Awakened Cockroach, Awakened Cockroach is able to block or dodge every attack by Genos, while sending out his own attacks. During their fight, Awakened Cockroach has the upper hand, until Genos decides to use instant adhesive to trap the monster, just in case if Genos encounters a speedster villains like that monster, including Sonic. However before Genos could kill the monster, Awakened Cockroach sacrifices his feet to get away. Furthermore, before Genos could make up his mind about returning to the stadium, another being rushes to Genos.

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

Monster Association Arc
Genos appears to save Death Gatling from Garou and attempts to fight him but is overwhelmed and almost killed before Bang and Bomb show up. Genos fights Garou and is nearly killed by him before Zombieman gets Garou's attention.

Fall of the Hero Association Arc
Genos appears to save 4 heroes from the Forest King.