Bang/Synopsis

History
Bang owns a dojo passed down from generations and uses the fighting style of Water Stream Rock Smashing Fist while his older brother named Bomb is the master of the Whirlwind Iron Cutting Fist. Bang invented the Water Stream Rock Smashing Fist while training under his older brother named Bomb. All of his scars came from his training trying to master it. Bang at 30 was considered unstoppable. Bang and Bomb often practiced martial arts together to the point of developing powerful combination attacks.

Bang once participated in Super Fight tournament to promote his dojo and won. At some point before the start of the series, Bang was ranked 77 in B-Class until he was moved up when the S-Class was formed.

He used to have many students, with his top student being Garou. One day, as Bang was away, Garou rampaged through the dojo, injuring many of Bang's students, including Sour Face, and incapacitating many others. Because of his actions, Bang beat up Garou and expelled him and because of the rampage, he lost all of his students, except Charanko.

Giant Meteor Arc
Bang is left with an impossible task by the Hero Association, to stop a meteor of a Dragon-level disaster that is on a collision course towards Z-City. At the Hero Association, he meets Genos to whom he explains the disaster. However, he claims that it is an impossible task and advises Genos to evacuate the city. When the siren signals warning everyone to evacuate, Genos wonders what Bang is going to do, to which Bang replies that he will protect his dojo. He turns around and asks Genos if he has ever heard of the Water Stream Rock Smashing Fist fighting style, but to his surprise Genos has already left the building.

Bang later shows up when Genos is preparing to attack the meteor. He sees that Genos is losing his composure and calms him down. Bang then watches as Genos attempts to and fails to destroy the meteor. Suddenly Saitama appears and, wondering who he is, Bang witnesses Saitama's strength by watching him destroy the meteor with a single punch. Bang also saves Genos from the debris of the meteor.

Bang later stands on a roof, watching Tanktop Tiger and Tanktop Black Hole as they attempt to break Saitama. He solemnly notes that Saitama, like all heroes, will have to bear this hatred even for their beneficial actions and take responsibility for it even when they do not deserve it and hopes that the hero industry will not break him on his road to become a hero. When the two Tanktop heroes declare a public challenge against Saitama, Bang identifies it as the common "newbie crushing" tactic combined with the public execution setup and notes that such a bold and reckless combination is what keeps Tanktop Black Hole in B-Class, indirectly referring to their overconfidence and inability to grasp Saitama's strength. He then leaves Saitama to resolve the problem on his own.

Alien Conquerors Arc
Bang is seen at his dojo demonstrating his technique for Saitama and Genos. When he asks the two whether they would like to attempt the technique, they refuse, causing Charanko to attempt to battle with Genos only to submit just as quickly. Upon inquiry as to the whereabouts of the rest of his students, Bang tells the story of his student, Garou, and how he was forced to punish and expel Garou after the student lost control and attacked and defeated several of the other skilled members of Bang's dojo. Saitama comments on Bang's strength, prompting Charanko into an uproar once again, this time over Saitama's ignorance of the legendary Silver Fang, and Bang reprimands his student for speaking out of turn to Saitama, whom Bang recognizes as several times stronger than himself. A messenger from the Hero Association then arrives and informs Bang that all S-Class Heroes have been summoned to A-City Headquarters due to a major crisis.

Upon arrival at Headquarters, Bang, Saitama and Genos encounter Atomic Samurai, who recognizes Bang and Genos, but not Saitama. Greeting Atomic Samurai in turn, Bang informs him of who Saitama is and expresses great confidence in Saitama's strength, stating that Saitama will soon make it to the top of S-Class. Bang is next shown at his seat in the meeting, asking about the reason the S-Class heroes have been called.

Later, A-City has been invaded by initially the Sky King, but later by the Dark Matter Thieves after the Sky King's death and the destruction of the city itself. Bang participated in engaging the enemies in combat along with Atomic Samurai, Metal Bat and Puri-Puri Prisoner. During their fight against Melzargard, Metal Bat exposes his weakness by destroying the vital marble that allows Melzargard to regenerate, thereby allowing the four S-Class heroes to successfully counterattack. Bang happens to aim at one of the marbles, but in the process, he let his guard down and received a direct blow to the side and was sent flying across the field.

Bang eventually returns to the fight bare-chested, without sustaining any damage, and helps to defeat Melzargard, finishing him off by driving his fist through his head and crushing the final marble that kept the monster alive.

Hero Hunt Arc
During the Hero Hunt by Garou, Charanko was "expelled" from his training and the dojo, only to find out later that Bang only wanted to protect him from Garou, who is hunting the heroes down and becoming a well-known threat to the Hero Association. Bang fears that his own strength might not be enough to stop his former student and called for help from his older brother Bomb. However, they are too late to find him, instead finding the carnage from the beaten forms of the Tank Topper Army, Mumen Rider, and Charanko.

Monster Raid Arc
During Bang's and Bomb's search for The Hero Hunter, his brother notices that one of their marked A-Class heroes is being attacked and the two martial artists rush to the scene. Smile Man is struggling against Fist Fight Djinn. Bang tells Bomb to stay back as he approaches the monster. Fist Fight Djinn boasts about his power, but before he could finish talking, Bang unleashes his anger through a barrage of attacks, breaking every bone in the monster's body. Afterward, he tells Bomb to continue the search for Garou before he becomes a true monster.

Monster Association Arc
When Genos begins to incinerate a weakened Garou after a brief intense fight, Bang comes to intervene in the process by kicking Garou in the face. Bang says hello to his former student, lamenting his terrible condition, deciding to put him out of his misery once and for all. Bang tells Garou to take a stance, and the two martial artists prepare to fight each other in a one-on-one duel. Garou initiates the first attack, but before he can even react, Garou is pummeled with a burst of quick and powerful blows by Bang.

Bang continues to pummel Garou with his attacks and when the former student tries to counterattack, Bang expertly blocks it and uses his Water Stream Rock Smashing Fist, overwhelming Garou. Garou tried to use Death Gatling as a meat shield, however Bomb blocks his attempt and both brothers combine their martial arts against Garou. As they were about to land the finishing blow, Garou surprises them by destroying the ground and swinging a huge tree at both Bomb and Bang forcing them to back off. Bang tells Garou to surrender, but was surprised when Phoenix Man swooped in and saved Garou, while calling Elder Centipede to cover their escape. Bang noticed the collateral damage the monster caused so he and his brother save the unconscious heroes from their demise. Bang combines his strength with Bomb and Genos and managed to significantly damage Elder Centipede with Bang and Bomb's combination attack, Roaring Aura Sky Ripping Fist, however, the monster's regeneration and molting allow it to recover and become larger and angrier. Furthermore, Genos' plan to destroy the monster from the inside failed. The trio decide to retreat, but as they were getting closer to the edge of the park, Bang decided to sacrifice himself to buy time for Bomb to escape with the unconscious heroes and Genos. Fortunately, King arrives and catches Elder Centipede's attention by tricking him into believing that he brought Blast with him, as well as taunting the monster, making the monster charge toward the S-Class hero. Bang is resting at Saitama's Apartment. Saitama leaves to find Garou and buy cabbage but when he comes back Bang is concerned over a big problem Saitama is suffering from. It turns out Saitama lost his wallet and Bang is relieved it is such a small issue. Genos, Saitama, Bang, Bomb, Fubuki, King and Dr. Kuseno all stare at the delicious hotpot. They all fight for the food. Bang chastises Genos and Fubuki as the fun in hotpot is sharing all the while he is hogging all the tofu. Saitama and Bang discuss raising disciples and Bang wonders if his methodology of the strongest ruling was the wrong path in raising his pupils. He heads out after the hotpot.

Bang is at the Hero Association HQ with his brother to get a replacement for his phone as it was destroyed in the previous battle. He meets with Sitch to order his new phone and asks about any updates on Garou's location. Sitch asks why Bang let Garou go before leaving. Bomb remarks that the Hero Association is suspicious of him for letting Garou go. Bang replies that he did not hold back. King enters the room and Bang coaxes information about the rescue operation from him. They decide to team up to attack the Monster Association's base together and decide to meet up at Saitama's Apartment. Bang and Bomb arrive at the apartment to find Genos and Fubuki there but Saitama missing. King arrives soon after and they decide on Genos to wait for Saitama while the rest heads towards the base. Bang, Bomb, and Fubuki are seen feeling the Monster Association's HQ shaking from Saitama's punch on Overgrown Rover and later protect Fubuki from Orochi's lightning. Their path is soon blocked by the Dragon level threat Overgrown Rover, who attacks them with its energy blasts. While temporarily enhanced by Fubuki, Bang and Bomb unleash Whirlwind Water Stream: Cross Fang Dragon Slayer Fist on the monster. While not destroying the monster, it led to it abandoning the fight as Bang expressed his annoyance at its durability and told it to sit.

Bang, Bomb, and Fubuki are eventually pulled out of the ground by Tatsumaki, joining the other heroes to plan the attack against Psykos and Orochi. Bang says that he knew Child Emperor purposely excluded them from the operation, but ultimately agrees that the young hero was right in considering his leniency towards Garou. He says that he will take responsibility of putting Garou to rest himself, and that he is in debt of Child Emperor as it gives him the chance to do so as a teacher instead of as a hero. As the plan to attack the Psykos-Orochi fusion is put in motion, Bang and Bomb appear after Genos, Drive Knight, Atomic Samurai, Puri-Puri Prisoner, and Superalloy Darkshine do their respective special moves against the fusion, with Tanktop Master providing support. After Darkshine's attack, Psykos separates from the fusion and the two brothers use Whirlwind Water Stream: Cross Fang Dragon Slayer Fist on Orochi to finish off the monster. Once done with his attack, Bang lands on the ground, thinking to himself that the S Class heroes are finally working together. When Bomb states that Garou is likely dead after Tatsumaki's attack, Bang warns him that he likely won't die that easily and that they have to keep their guards up. He and Atomic Samurai then express concern for Flashy Flash, who was still under the base, but Tatsumaki states that she didn't sense him underground.

As the Monster Association Executives resurface, Bang observes as Tatsumaki is being chased down by a massive amount of Homeless Emperor's energy spheres. However, that is revealed to be a decoy of her and the esper then appears to Bang, Bomb, and Fubuki in an exhausted and weakened state due to the battle with Psykos and Orochi. After a brief talk between Tatsumaki and her little sister, Bang along with his brother and Fubuki are temporarily restrained by Tatsumaki's psychic binding so that the esper hero could fight on her own. Right after Tatsumaki takes her leave, Genos states firmly that he will assist her, much to Bang's disagreement with him saying that it is too reckless and that Genos could explode soon. However, the cyborg reassures him and then leaves to help the injured hero. Noticing that the bind from Tatsumaki disappears and that his arms and shoulders are no longer sore, Bang too decides to do his part and aid Tatsumaki, telling Bomb to take care of Fubuki and let him know if he sees Garou. Bang swiftly comes to the aid of Tatsumaki and Tanktop Master by kicking a hole through Gums and saving the latter. Bang is then noticed and attacked by Fuhrer Ugly's Face Caving Punch while he is in the air, however the martial artist is able to meet the punch with a kick, redirecting it back to the monster's face. Back on the ground, Bang notices as Tanktop Master's heartbeat has stopped. He attempts to lift Tanktop Master's shirt up to allow Genos to defibrillate the fallen hero, however he loses his grip due to the tank-top's tightness. The snap-back from the tank-top is enough to restart Tanktop Master's heart and revive him. As he checks up on Tanktop Master's condition, Bang then notices as Gums launches a sneak attack on Genos, while Fuhrer Ugly once again challenges the martial artist. Bang warns Fuhrer Ugly that the executive's attacks won't work on him due to his Water Stream Rock Smashing Fist, however the monster does not heed this warning and attempts to use his Dignity Caving Punch against the hero. Bang is able to swiftly redirect the attack once again, this time towards Gums and causes it to spit out Genos. He then launches a flurry of blows against Fuhrer Ugly, knocking him back as Gums comes behind the ugmon and eats the fat monster. As Bang and Genos run away from the scene, he notes that Tanktop Master's worsening condition will have to force them to use Fubuki's healing abilities again despite not wanting to overburden her.

Bang and Genos are then stopped in their tracks by Black Sperm, who then multiplies itself and attacks the heroes. Although Bang is able to redirect the attack with a kick, Genos is hit. Unable to assist the cyborg, Bang puts down Tanktop Master in preparation to defend himself from the horde of Black Sperm clones that have multiplied and surrounded him. As Bang uses his Water Stream Rock Smashing Fist to destroy the Black Sperm clones, Atomic Samurai comes to his aid by using his Atomic Slash to cushion Genos' fall by turning the rock into smaller chunks of debris and dust. Bang then leaves Atomic Samurai behind to take care of Black Sperm per the swordmaster's words and thanks him. Despite this, Bang and Genos are still relentlessly pursued by a horde of Black Sperm's clones. Allowing Genos to carry both Tanktop Master and Tatsumaki, Bang is forced to continuously use his martial art to defend themselves from the Black Sperm clones, however he begins to note that he may not be able to hold them off at this rate. As a wounded Tatsumaki then begins to assist both heroes, Bang stays behind to assist the wounded esper and tells Genos to get Tanktop Master out of there.

Later, when the members of the Council of Swordmasters come to the heroes support, Bang continues to fend off countless clones of Black Sperm surrounding along with them and the other heroes. While defending himself against Black Sperm, he hears Bomb loudly call his name, and is informed by his brother that Garou is there with him. As Bang hesitates about leaving his current spot and heading towards the former disciple, Atomic Samurai tells him to go and leave the place for him and the others, much to his gratitude. Bang then arrives at Bomb's whereabouts, only to witness his older brother already lie defeated against the fallen former student. With seemingly a sad expression on his face, Bang looks at Garou as they prepare to engage in combat.