Since its debut, My Hero Academia has exploded in popularity, becoming a staple in Shonen Jump's current generation of manga and anime. Even those less familiar with the series can recognize protagonist Izuku Midoriya from his bright green hair to his extravagant Quirk, One for All.
Manga creators often go through many drafts of a character before settling on the final design, and Izuku was no exception. In fact, the original idea for his character was a huge contrast to the hero we know him as today.
It's hard to imagine Izuku not as a bright and strong-willed high schooler, but in the original My Hero Academia one-shot titled "My Hero" -- released in Akamaru Jump's winter 2008 issue -- the protagonist of this superhero-based world is an adult named Jack Midoriya. Jack is a sickly salaryman who works for a company selling hero support items. Despite his frail body, he still dreams of being a hero and tries to achieve this by using the tools from his own company to be a vigilante.
Thankfully author Kohei Horikoshi rewrote the story and, in an early concept of My Hero Academia, came up with a character who would later be recognized as Izuku's prototype. This character was named Mikumo Akatani, a Quirkless high schooler with big dreams of becoming a hero and a knack for analyzing and gathering information. Sound familiar?
This is where Izuku and Mikumo's similarities end, however, with Mikumo taking a route similar to DC's Batman. For starters, while Izuku obtains One for All from his mentor All Might, Mikumo stays Quirkless. With his analytical ability, Mikumo relies on gadgets and luck to stand on par with his peers, all of whom have Quirks -- much like the powerless Batman fighting side by side with other DC heroes. Meant to act more like a vigilante than a hero, this aspect was changed due to editorial intervention.
The prototype also had a much edgier design consisting of long, black curly hair that covered one of Mikumo's eyes. Always drawn with a broody expression, he looked more like an antihero than your average superhero. He was also given an extra edge with an intimidating hero costume following Batman's animal theme, but with rabbits. Interestingly enough, this antihero-like costume seems to have been kept on the back burner as it was recently adapted into Izuku's latest costume redesign in the manga.
It's no secret that Horikoshi is a big fan of Marvel and DC with much of his inspiration for My Hero Academia coming from western comics. As such, Mikumo's list of similarities to the Caped Crusader was probably no accident. But Horikoshi eventually found his own unique style of storytelling and has settled on other, more subtle ways to include his love for Marvel and DC in his manga.