Bomb at 32 was considered unstoppable. Bomb and his younger brother Bang often practiced martial arts together to the point of developing powerful combination attacks. Bomb ran a dojo teaching students martial arts. He shut down the dojo to help Bang hunt down Garou.
Bomb is first seen in his dojo in a meeting with his brother Bang. Although he does not know Garou himself, he talks about how he heard that he is a threat and must be taken down. Therefore, he prepared to close his dojo and say farewell to his students for their own safety. He agrees on hunting him down alongside Bang after a short conversation. Bomb and Bang later arrive on scene of the badly beaten Tank Topper Army, Mumen Rider and Charanko, who had been hunted down by Garou.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. Afterwards, he tells Bomb to continue searching for Garou before Garou becomes a monster.
After Bang and Bomb arrive at the fight between Garou and Genos, he helps his brother dispose of a monster nearby by using his Whirlwind Iron Cutting Fist martial art technique to mince a monster into pieces.
When Bang prepares to fight Garou, Bomb states that he will take care of the rest of the monsters. After clearing the majority of monsters, he appears in front of Garou and kicks him in the face to prevent him from using Death Gatling's body as a meat shield. Soon after, 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. He and his brother save the unconscious heroes from their demise.
Bomb combines his strength with Bang and Genos and managed to significantly damage Elder Centipede with him and his brother's combination attack, Roaring Aura Sky Ripping Fist, however, the monster's regeneration and molting allow it to recover and become larger and angrier than before. Furthermore, Genos' plan to destroy the monster from the inside fails. 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 it charge toward the S-Class hero. Bomb then witnesses the demise of Elder Centipede at the hands of Saitama and is shocked and impressed at the power of the young hero.
Bomb is resting at Saitama's Apartment where he greets Fubuki at the door. Bomb complains about pain in his knees after pulling off Roaring Aura Sky Ripping Fist as it had been a while since he performed it. Bomb worries about Bang, especially if they continue to face monsters of the same level as Elder Centipede, and suggests for him to retire from being a hero. 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 much to Bomb's dismay. Fubuki questions why an ordinary old man like Bomb is there and that he will need to prove himself to join the Blizzard Group. After the hotpot, he leaves for the night.
The next day Bomb joins Bang at the Hero Association. After Sitch questioned Bang's actions on Garou, Bomb then remarks that the Hero Association suspects that Bang went easy on him and didn't finish the job because of his relation to him. King then enters the room and informs them both about the rescue operation. They decide to join the operation and use King's route to get into the Monster Association's base along with Genos and Saitama. They then plan to meet at Saitama's Apartment. Bomb and Bang arrive at the apartment to find Genos and Fubuki but no Saitama. King arrives soon after and Bomb hears Fubuki planning to join their attack. King proposes they wait for Saitama before heading off, but Genos decides to wait for him while Bomb and the rest head out to attack the Monster Association Headquarters.
Bomb and the others' path is soon blocked by the Dragon level Overgrown Rover who attacks them with its energy blasts. After Fubuki aides them with a part of her psychic powers, Bomb and Bang try to subdue the Monster Association executive with their Secret Combination: Cross Fang Dragon Slayer Fist.
After burying the monster, Bomb's battle prowess impresses Fubuki who tries to recruit him.
They prepare for another round with the monster when his Bang manages to tame the monster by telling it to sit. They hurry onward and Bomb's confidence is shaken by fighting another monster that took his special attack with minimal damage.