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 inherits All Might's Quirk. Izuku is accepted into U.A. Academy and meets a lot of other heroes.
The saga talks about how one day a Luminescent Baby was born in Quig Quig, China and had an "individuality". Soon everyone across the world would develop what they call a Quirk or a special power. These powers would then let people become heroes or villains.
The saga also happens when Izuku starts U.A. and has to meet the expectations of the school.
We are introduced to two of the major villains in the series, Shigaraki Tomura and Kurogiri. Their goal is to kill All Might so there will be no symbol of peace and that would cause Japan to go into chaos.
After the Sports Festival, the students of Class 1-A get to train with pro heroes. Izuku trains with Gran Torino to control his Quirk. While out on training, they are attacked by three Nomus and Stain. Tenya Iida, remembering what happened to his brother at the hands of the Hero Killer, wants to get revenge on Stain for hurting his brother. Stain is defeated by Tenya and his classmates, Izuku and Shoto. After the fight Tenya regrets what he did.
The End of the Term is here before the summer break, so the students have to fight against the teachers at U.A.
Aizawa now announces a school trip to help the students improve their Quirks and Teamwork skills. The League of Villains then attacks the students and wants to capture Katsuki and turn him into a villain.
All the pro heroes gather together and form a team to raid the League of Villains hideout and rescue Katsuki. Izuku and others go undercover in order to find Katsuki and bring him back.