Koichi Haimawari & Heroes vs. Bombers is a battle produced because of the attempted murder of Captain Celebrity by the Scarred Man, who sends five Bomber against him. First Koichi and then several pro heroes, help Captain Celebrity in the battle.
For several weeks, the villain known as Scarred Man intends to kill Captain Celebrity, using a new type of Next-Level Villain known as Bombers, for his ability to self-destruct with a powerful explosion. Scarred Man already used one of these creatures to attack the Captain and thus study his abilities, thus discovering the weakness of his Quirk. With the information obtained, he plans a new attack to end his life.
Recently, it was announced that on the occasion of the return of Captain Celebrity to the United States, a farewell party will be held in his honor at the Tokyo Sky Egg, a 500-meter high tower with a dome on top. This show will be attended by some of Japan's most famous heroes, such as Best Jeanist, Edgeshot, Ingenium and many others. That will be the day and place where Scarred Man will perform his attack with a large number of bombers.
However, just when the show is about to start, the laboratory where the bombers are created is assaulted by a police force led by Detective Naomasa, and with the help of the Heroes Eraser Head and Fatgum. Scarred Man is forced to blow up most of the Bombers to end this threat and destroy the laboratory and all evidences. Scarred Man escapes the explosion by grabbing the leg of one of the five surviving Bombers. Despite this setback, he decides to continue with his plan to kill Captain Celebrity, heading with the Bombers to the Tokyo Sky Egg.
Due to a misunderstand with his wife Pamela at cell phone, Captain Celebrity leaves the stage to try to solve the situation with her. After the performances of several heroes, Makoto sends Koichi to look for Captain Celebrity, because soon he must back on stage. Koichi finds him in the Observation Deck, still apologizing to Pamela, when he looks out and sees a building on fire, and five creatures flying straight towards them, discovering to his horror that they are exactly the same as the one that attacked Captain Celebrity weeks ago. One of the Bombers sticks to the crystals of the observatory and explodes. The decompression drags Koichi outside, falling from several hundred meters in height. Thanks to his quirk, Koichi manages to hold on to the tower and not fall to the ground.
Captain Celebrity immediately goes outside, and after checking that Koichi is all right, he prepares to face the Bombers. One of them explodes but hardly affecting him thanks to his aerodynamic barrier, but everything turns out to be a distraction. An especially large Bomber clings to the Tokyo Sky Egg’s tower and it self-destructs in a big explosion that seriously damages the structure. Due to the damage, the Tokyo Sky Egg could fall at any time, killing thousands of people. To prevent this, Captain Celebrity uses his enormous strength to hold the building, but this leaves him helpless.
Everything is coming out just as Scarred Man had planned, and he sends a Bomber to attack Captain Celebrity. This Bomber has been specially designed to face Captain Celebrity because it has six arms, can throw explosive punches, and has the ability to regenerate any lost limb. The creature mercilessly attacks Captain Celebrity, but despite the punishment he received, he continues to hold the building, ensuring that he can withstand hundreds of those attacks.
Inside the Tokyo Sky Egg dome, both everyone is wondering about the many tremors rocking the dome. To prevent the interference of heroes and any contact with the outside, the Scarred Man send the other remaining Bomber to the dome’s roof of the dome to generate an EMP blast. This causes a blackout in the building and renders all electronic devices useless, completely isolating the people locked there from the outside.
In one of the rooms of the Sky Egg, the heroes and show staff discuss the situation. Best Jeanist deduces that everything that happened follows a meticulous plan by someone to seal them all in the building. He decides that the best option is for the show staff and a group of heroes to look after the civilians without telling them the truth about what is happening to avoid panic. Meanwhile, another group of heroes go to a small access hatch at the top of the dome where the heroes capable of flight will exit and make contact with the outside.