In Neo-Tokyo, built on the former site of Tokyo after World War III, two teenagers are targeted by agencies after they develop paranormal abilities.

"Mutants are all around us. Some are good, others unspeakably evil. But they are all gifted, gifted with a unique X-Factor in their genetic makeup that makes them living weapons, manifesting itself through wondrous powers. And, even within this special community, there is a group that has distinguished itself the uncanny X-Men who have honed their awesome abilities and pledged them in the service of mankind. Gathered by the mutant telepath, Charles...

Midoriya inherits the superpower of the world's greatest hero, but greatness won't come easy. What would the world be like if 80 percent of the population manifested superpowers called Quirks? Heroes and villains would be battling it out everywhere! Being a hero would mean learning to use your power, but where would you go to study? The Hero Academy of course! But what would you do if you were one of the 20 percent who were born Quirkless? The Hassaikai...