CH 1: "First Light"

Radianite, a powerful substance that is able to power three quarters of the globe.

If one is exposed to it, it grants the person increased strength, and some who received permanent abilities were called "Radiants".

In a world filled with quirks, radianite would be considered a steroid for those who wanted to get stronger, and yet, those with quirks who were in the vicinity of radianite, died before they even saw it.

This is why radianite is locked away and managed by quirkless people, and there has been a divide, between the people who use radianite, and the people who have quirks.

Izuku Midoriya is a radiant who was recently recruited because a man named Yoru saw potential in him.