Boku no Here Academia

The literal zero to here as the story follows Deku, a boy who dreams to be as great as the heroes he sees all around him. But there's one thing...he has no powers! Bummed out by this, he starts gathering information on existing heroes. One day while walking around, he sees his favorite hero All-Might! However, All-Might looks frail and skinny which is not normal. 

Deku learns that All- Might has started to lose the grip on his powers ever since fighting a particular monster. All-Might chooses that Deku should be adorned with his power. And that's just the tip of the iceberg.