Izuku was a little hero with no power,like the others.At 4 years old all the children got a power.

But him not. Untill a day when Izuku Midoriya sees his hero idol. He sees All Might.

Then All Might give his power after he puts Izuku to clean the beach.Izuku to have All Migth's powers he was forced to eat a hair from All Might.

Then Izuku got his powers but he can't control them.So at the Hero Academia UA he hurts for saving Uraraka from the robot.