U.A. Beginnings Saga

The U.A. Beginnings Saga is the introductory saga of the series. Izuku Midoriya, a young boy who was born without a Quirk, dreams of being a hero some day. At the beginning, he is bullied by Katsuki Bakugo and eventually meets and inherits the Quirk of the No. 1 Hero, All Might. After some training to be able to accept One For All, Izuku is accepted into U.A. High School, where he meets and soon befriends his fellow hero students.

Izuku learns to adjust to his new environment, as well as attempting to harness the power of One For All, which destroys his body every time he uses it. The students of Class 1-A are one day attacked by a group known as the League of Villains, and their leader Tomura Shigaraki, who desires to kill All Might so there will be no Symbol of Peace, which would throw Japan into chaos. They fail in their plan and Tomura is forced to retreat.

The students then take part in the U.A. Sports Festival, which gives them all the opportunity to show off their Quirks and skills to the world. Amongst all the alliances and declarations, Izuku learns about the tragic past of Shoto Todoroki, and manages to help him learn to accept himself for who he is. Katsuki becomes the Champion after defeating Shoto in the final battle.

After the Sports Festival, the students take internships where they get to train with Pro Heroes. Izuku trains with All Might's former master, Gran Torino, to gain control over his Quirk. While out training in the city of Hosu, they find themselves in the middle of an attack by the League of Villains' Nomus. He also rescues Tenya Ida from the Hero Killer: Stain, who Tenya was seeking out for revenge, and with the help of Shoto, Stain is defeated. However, his defeat leads to the unintended consequence of more villains starting to follow his ideals, and wishing to join the League of Villains.

With the end of school term coming up, All Might reveals to Izuku the truth behind the origin of One For All, and the mysterious villain All For One who he believes is secretly behind everything. Meanwhile, the students have to take their Final Exams where they must face against the teachers in battle. Izuku and Katsuki are forced to team-up to take on All Might, and barely succeed.

During summer break, Class 1-A are taken to a summer training camp to help them improve their Quirks and teamwork skills. However, the League of Villains suddenly attack the students, and successfully kidnap Katsuki, with the plans of swaying him into a villain.

A team of Pro Heroes gather together and form a plan to raid the League of Villains' hideout and rescue Katsuki, while Izuku and others go undercover in order to save him themselves. This culminates in the arrival of All For One, who after a devastating and hard-hitting battle, is defeated by All Might, at the cost of him losing the remaining embers of One For All, and retiring as a Hero.