Midoriya Izuku was just a regular middle school student in a world where people with superpowers known as Quirks are the norm. However, he dreams of one day becoming a Hero, despite being bullied by his classmates for not having a Quirk. After being the only one to try and save his childhood friend Katsuki from a Villain, All Might, the world's greatest Hero transfers his own quirk, One For All, to Midoriya. The story follows Midoriya's entrance into Yuuei High School, a Hero Academy that aims to train and raise their students into great heroes. Source: Wiki (edited)