Author's Note: This is an idea that came to me recently and that I have not been able to get out of my head since. The approach to this is inspired a bit by the story Miracles by half_sleeping, as well as a few now-deleted stories I read a while back about a female Captain America. However this will be its own separate story, regardless of the inspiration. I look forward to exploring this world, moving forward, and am excited to see it develop as we progress further into the story! I hope you all enjoy it just as much. :)
Midoriya Izumi was with Bakugou Katsuki the moment her life changed forever.
The two girls had been sitting in Katsuki's living room watching the hero channel and exclaiming excitedly every time their favorite heroes showed up. Their hands were clenched around the figurines of various heroes, and during commercial breaks they acted out several of the fights they had just seen. The latest clip had been of their current favorite hero, Leverage the Strength Hero, taking a robber into custody when the scene suddenly switched.
First there was a backdrop of burning rubble, flames licking the sky in a hellish orange glow. Reporters' voices were alarmed, murmuring incoherently in the background as people rushed back and forth. Then rising up out of the rubble, blonde hair, muscular arms, and the limp forms of civilians draped over broad shoulders. A wide grin exposing teeth as laughter burst from the figure.
"It's fine now. Why? Because I am here!"
The figurine of Leverage fell from Izumi's suddenly numb fingers as she gaped at the screen, eyes wide in shock. Beside her, even Katsuki had fallen silent in her surprise. Even the reporters on the screen had hushed, containing a quiet awe evident even through the screen.
On-screen the hero stood tall, several civilians draped over their shoulders as they carried no less than six people from the wreckage at once. Their smile never wavered, their confidence never eased. Long hair whipped and snapped about in the rush of heat from the flames, and blue eyes stared challengingly into the cameras.
That day was the day All Might made her debut into the world of heroes, only to then go on to become the first female hero to make the top fifty list. Then the top twenty. Then the top five. Then number one.
That day was the day Midoriya Izumi realized she wanted to be a hero.
The next several years saw a surge of female superheroes entering the scene. Women who were already in the industry found their popularity growing faster than ever before. Experts in the industry scrambled for explanations, to make adjustments, to promote their own new heroines.
Throughout it all, All Might's popularity continued to rise.
Marketers tried to recruit her to promote their clothing lines, to wear their makeup for interviews, to advertise their products. All Might never responded to their calls and emails, and when questioned in one particular interview, stated that a paycheck wasn't why she got into the business. She declared that her only goal was to save as many people as possible with the time that she had as an active hero.
After that interview, her popularity only grew, and it became one of her most quoted videos ever.
The eyes of the world remained on All Might as she continued to rise - some in awe, some in hate, and some in envy. They watched as she performed feat after incredible feat, things many would have considered impossible, and stayed smiling throughout it all. Little girls across the world looked to her and began thinking If she can do it, why can't I?, and their dreams shifted towards heroism.
Decades after All Might's time had come and gone, people would credit her for the ability of women to have the chance to become successful heroes, as well as for the ideals that shaped the generations of heroes that followed her.
While superheroes and supervillains had come into being almost as soon as Quirks did, there was a shift in the culture around them after All Might arrived - it was an undeniable truth.
Where female heroes in the media were either non-existent or delegated to sidekicks before, now they got their own segments. Heroes started selling merchandise as All Might's agency signed deal after deal, allowing her image to be used. People began to notice when the people around them were being mistreated, and began standing up for them with thoughts of heroism in their head, and ideals of peace, honor, and courage on their lips.
With the coming of All Might, it was more than a new hero entering the scene, and more than a change in mindset and culture. It was a revolution, simple as that, and it took the world by storm.
I noticed that we only see the history of heroes from Izuku's point of view. It is heavily biased towards All Might because he is such a fanboy, and skips over a large portion of information between the first Quirk and hero-obsessed world that we see in the show. This is an attempt to begin addressing that (as well as the fact that there are significantly more successful male heroes in the show than female heroes), and it also implies that All Might is the reason society's hero-culture is the way we see it in the show. It is canon that in-show All Might had a huge impact on the hero world, and this is my interpretation of that in this world.