Not all men were born equal, but they were all equally tiny compared to women.
It had all begun back in the mid-21st century, when a baby had been born in China with a very unusual feature: she glowed from all over her body. The Glowing Baby, as she'd come to be known by, was the first documented case of a person being born with a genetic mutation that gave them unusual features or abilities-their Quirks, as the phenomenon would eventually be termed.
A few months later, another unusual baby was born in Russia with what had initially seemed like another quirk; he was born at less than a quarter inch tall. At first, everyone had assumed it was a one-off, that this was not connected to the baby in China. But then another boy was born in England with a Quirk that gave him scaly skin, and he was also less than a quarter of an inch at birth. Both baby boys would later only grow to about an inch tall.
As more tiny male babies-both with and without Quirks-and more baby girls with Quirks were recorded over the next few years, it became clear that something had caused the human genome worldwide to change, and as these changes were triggered they were not only causing people to develop new powers but also limiting newly born males to tiny sizes. In just five years, over a third of all male children being born were tiny, and Quirked children of both biological sexes were found on every inhabited continent.
In around twenty-five years, society had collapsed in the event known as the Dawn of Quirks, unable to cope with the rapid spread of superpowers and the even more rapid loss of full-sized male children. With the loss of manpower, many industries and businesses, especially male-dominated professions, collapsed or went into decline, while superpowered criminals took advantage of the chaos. In forty years, no normal-sized baby boys were being born at all, and the world male population began its inevitable slide to being the much smaller sex.
But society had, eventually, managed to come back from the brink thanks to the efforts and sacrifices of many brave young women and tiny young men. As the first generations of women born with Quirks realized someone had to step up to fill the void, they began to use their powers to fight crime themselves and help others. And many young men chose to help them in whatever way they could at their tiny size, those with useful Quirks using them to compensate for their relative lack of strength and some even being able to rival their enormous female counterparts in combat prowess. It wasn't long before various world governments, desperate for stability, took notice and began to recruit some of these vigilantes to rein in both criminals and other vigilantes. As these newly appointed Quirked public servants expanded into other first responder roles, a once-fictional occupation became reality: professional heroes.
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In Musutafu, Shizuoka Prefecture, Japan, as the first rays of the sun rose above the horizon, a green-haired teenage boy opened his eyes and got out of bed, eager to start the day ahead. His name was Izuku Midoriya, and this was going to be his first day of high school....and not just any high school, but UA High School, the best hero academy in Japan!
Izuku had always idolized pro heroes and wanted to become one himself, but it had been a forlorn hope for most of his life. Not only was he male, and thus physically much smaller and weaker even compared to some insects, he was unlucky enough to be part of the 20% of humanity that didn't have a Quirk. He'd spent his whole life being bullied and looked down on by both his male and female peers, especially Kacchan-his childhood friend who'd looked down on him ever since he got his own Explosion quirk, and had even given him an insulting nickname, "Deku".
But everything had changed one fateful day last year, when Izuku had managed to catch the eye of not just any pro hero, but All Might himself, his personal idol. Even better, he'd been given the chance of a lifetime; the chance to inherit One for All, the strongest quirk in the world. It had been a mystery as to how All Might managed to be so fast and powerful, especially since he was male yet was stronger than any female hero or female villain out there. Not only had Izuku been allowed in on the secret, he'd been chosen as the next hero to wield a power that had been passed across various heroes ever since the Dawn of Quirks. After ten months of intense training to toughen up his body in preparation, he'd received it, though he was still having trouble getting used to it.
Once Izuku had showered and gotten dressed in his new U.A uniform, he picked up his school backpack that he'd packed the night before. Checking to make sure he had everything he needed for classes, he walked out through his front door.....and onto the dresser table his "house" sat on.
One of the most fundamental changes that had occurred following the Dawn of Quirks was the development of miniaturized facilities and construction specifically for male usage. While public infrastructure had been extensively modified to allow for mixed-sex use, there was also a need for private housing that was both safe and comfortable for males, especially if they had to share living space with women. The solution was to build lightweight, portable housing units that could easily be customized with add-ons and could be placed within female housing to provide a "home within a home". They looked like dollhouses but were fully functional, with built-in plumbing systems, electricity, and a kitchen like a housing unit for females would-just at 1/68.898 scale.
He looked around the bedroom, starting with the door, the ensuite bathroom, and the half-open closet that his entire housing unit could fit inside five times over. Only then did he turn his eyes towards the enormous (for his 0.949" height) bed that took up about a quarter of the bedroom, and to the presence that dominated the room even in her sleep: his mother.
Inko Midoriya, a plump but still good-looking woman in her forties, peacefully snoozed away on her bed oblivious to her diminutive child watching over her. It was only from a vantage point like this that Izuku was able to take in her whole body, as whenever she was fussing over or snuggling with him she was simply far too gigantic to fit inside his view.
Her green hair, which she liked to have Izuku play hide-and-seek in, was splayed out around her vast face. Her mouth was held slightly open, but even then it was big enough to engulf him-he was always in awe during dinnertime seeing his mother swallow mouthfuls that were many times his size. Her mountainous breasts formed great mounds that rose from the landscape of her body, each over four and a half times as tall as him.
Her immense, soft bottom, though currently concealed under the covers, created an obvious round bulge in the landscape of her bed that would loom over Izuku like a tall hill had he been down on the bed with her. When he was a very young child he actually used to enjoy climbing around and exploring his mother's massive posterior, pretending that he was a hero chasing a villain into the "canyon"; nowadays he'd matured too much for that sort of play, even though his enthusiasm for all things heroes hadn't abated in the least.
Inko was a heavy sleeper, and the snores coming from her (which sounded more like thunderstorms for Izuku) were enough to tell him that he'd have to wait a while for her to get up. There was still plenty of time before class started, of course, but he'd seen his mother oversleep for hours. He still had to have breakfast before he went to school, and though there were male-friendly public transit services that he could take to get to UA, he still wanted Inko to see him off for his first day.
He thought it might be a good idea to go and wake her up if he wanted to not be late. Would that be worth the risk, though? He'd need to get to the floor first, somehow, in spite of the fact this woman-sized dresser was as tall as a large building for him. He'd done it before, but it wasn't always possible, and even if he managed to find his way down he'd then have to find a way to climb up Inko's bed, and then wake her up somehow-all without being smothered, crushed, eaten, or ending up deep between her buttocks (it had happened), among many other things his mom could accidentally do to him. Of course, things might be different now with all the physical training he'd done, but it was still a risk.
After some thinking, he decided that he would...