All Might

Toshinori Yagi, オール・マイト

The main character in this story is known as "All Might," who is considered the top hero and embodies peace. He's renowned for consistently rescuing people with an expression of happiness on his face. In terms of appearance, All Might resembles traditional superhero comic book characters, standing tall and muscular with a body full of shadows.

Spoilers:

All Might meets with All for One, the enemy who gave him his fatal wound, once more during the Hideout Raid arc. After a tough battle, All Might manages to defeat All For One, but ends up using all of his remaining power, ending his hero career once and for all. However, in his true form, he appears to be grossly underweight. During an encounter with a villain five years ago, he suffered life threatening injuries; the medical procedures that saved his life left him with an extremely frail physique. Now he can only serve as a hero for three hours a day, as his body cannot handle any more exertion.