Koichi Haimawari/Synopsis

History
When he was a baby, he was able to float before he could even walk. As he would tend to float out of his crib, and even towards roads into traffic, his worried mother would use her Fly-Swatter Quirk on him whenever he floated, possibly conditioning him into not using it and causing him to forget that he even had the ability.

Later on in life, Koichi started impersonating All Might while interfering in fights, putting himself in danger to help people. Koichi was determined to be a hero, but the morning of the high school entrance exam, he stopped to save a drowning child. He gave the child his silver age All Might hoodie to keep warm, and then rushed off to the exam, for which he was too late.

Synopsis
Koichi is watching a giant monster terrorizing the city. Suddenly, All Might appears and defeats the monster with ease. The public is awed at All Might's strength. Seeing that everyone is unharmed, All Might takes his leave. Koichi is inspired by heroes like All Might and wishes to be one like him in the future. Late for his job he uses Slide and Glide to move faster. However, a police officer stops and berates him for using his Quirk. After the police officer leaves, Koichi runs towards his next destination and expresses annoyance over the laws surrounding public Quirk use. Koichi runs into a group of thugs and knocks into Soga Kugizaki, which spills the juice he just bought. The thug orders Koichi to apologize by getting down and groveling. Soga prepares to step on Koichi, but the boy slides backward, which surprises Soga. Koichi slides away and escapes from the thugs.

Koichi sees another group praising a freelance idol, Pop☆Step. Koichi notes that she is taking a big risk in being a freelance idol since she does not have a permit. Despite her songs not being great, the aspect that stands out is her ability to fly which is what attracts some people to become her fans. A police vehicle is passing by, so Koichi warns Pop☆Step. As she ends her live performance, Koichi slides to his place of work. Koichi works at a convenience store; the manager is not pleased with Koichi being late and deducts his pay. Customers arrive, however, it is the same group of thugs that Koichi encountered earlier on. Soga becomes angry at seeing Koichi again and takes him outside. Soga beats Koichi up; Koichi is unable to fight back because Soga threatens him with spikes. After being forced to buy juice for Soga, Koichi is annoyed at being beaten up and changes into his "suit", an All Might-styled jacket with a hood and wears a mouth mask. Koichi decides to deliver justice on his own accord without being bogged down by the law.

Koichi starts doing good deeds for the public such as returning dropped items, giving directions, helping people get onto trains, being a cameraman, and recycling. The citizens thank Koichi and refer to him as Nice Guy. Koichi feels overjoyed in helping people as it relieves him of stress and makes him feel warm inside. With his good deeds done for the day, Koichi begins walking home. Suddenly, Pop☆Step hands Koichi juice to drink. She thanks him for warning her about the Police and followed him in order to properly thank him, but mocks Koichi for being weak, to which Koichi defends himself as being poor at dealing with violence.

Pop☆Step finds it ironic that Koichi is wearing an All Might hoodie but is bad at fighting. Koichi wears the All Might hoodie because it symbolizes his ideal in being useful in his own way. After they scrutinize each other for their objectives, Pop☆Step begins leaving but bumps into Soga. The thugs recognize her as the online idol and begin mocking her. Koichi tries to stop them, but the thugs ignore him. Koichi sees tears in Pop☆Step's eyes and cannot ignore her plea for help. Koichi theoretically wonders how he can handle the situation; use his Quirk to trip two of the thugs and take out Soga by tackling him so that Pop☆Step can fly away.

Koichi decides to put his plan into motion but fails to knock over Moyuru Tochi, who picks up and throws Koichi to the ground. The thugs turn their attention to Koichi and Soga scratches Koichi's face with spikes from his foot. Soga decides to finish off Koichi for annoying him and then to strip down Pop☆Step.

As Soga prepares to strike, Knuckleduster interrupts, crashing down onto a trash heap. Suddenly, the old man punches Soga, knocking him down to the ground and surprising Koichi. The other two thugs are shocked at what transpired and ask for the old man's motivations. He tells them that he specializes in dealing with hoodlums. Knuckleduster defeats the two thugs and checks their tongues as he is looking for signs of Trigger. Knuckleduster turns his attention to Koichi and praises him for his efforts, telling him that he can become a real Hero if he works with him. Koichi shows no interest, but Knuckleduster can see through his lies and knows he is someone who cannot abandon people in need, like All Might. Koichi admits that his Quirk is not useful and could never pass the Pro Hero Exam. Knuckleduster does not care about whether Koichi has a powerful Quirk or license because they have absolutely nothing to do with justice. Knuckleduster believes that true Heroes take action when something rises up before them. Koichi realizes that Knuckleduster is unlicensed.

Suddenly, Soga takes Pop☆Step hostage, threatening to claw her face off. Unable to let him get away with his atrocious act, Koichi charges at the thug and knocks him down, allowing Pop☆Step to fly above for safety. Knuckleduster punches Soga into the wall, which knocks him out. Knuckleduster sees that Soga is not in possession of Trigger and makes a copy of his ID. Knuckleduster informs Koichi that there are more ways to be a Hero than what the world says; Knuckleduster is a hero because punishing evildoers is refreshing. However, Koichi finds Knuckleduster to be dangerous and turns down his offer.

Koichi then returns to his apartment, only to find Knuckleduster there. Knuckleduster then informs him about Trigger. He attempts to prevent Knuckleduster from going too far while looking for Trigger users and meets Pop☆Step.