Note: No dates have been established relative to our calendar, outside of "the future", and even then, there's some things that don't have a concrete date and can only be placed based on other info.Spoilers will be off
First Quirks appear
Formation of All for One and One for All
First Person to have One for All
- All for One amasses followers with his power to remove and give quirks at will.
All Might's Predecessors
Second Person to have One for All
Third Person to have One for All
Fourth Person to have One for All
Fifth Person to have One for All
Sixth Person to have One for All
- The sixth user dies young due to an undisclosed event.
Seventh Person to have One for All: Nana Shimura
- Nana Shimura gives her son, Kotaro Shimura, to social services in order to keep him away from the villains she fights.
- All Might gets One for All.
- Nana teams up with Gran Torino in order to teach All Might.
Eighth Person to have One for All: All Might
- All Might trains and studies in America to be away from All for One, after his mentor's death in the hands of their nemesis.
- All Might befriends and makes a sidekick out of David Shield while in the US.
Timeline of the Meta Liberation Army (Unknown generations)
- The "Mother of Quirks" dies, protecting her son from an anti-quirk faction. Her sacrifice is moving. The term "quirk" she uses is later officially adopted by the government to refer to powers.
- Moved by the death of his mother, Destro/Chikara Yotsubashi creates the Meta Liberation Army.
- In an unknown moment, Destro impregnates an unknown woman and has descendants.
- The Meta Liberation Army is busted. Many high-rank members are arrested including Destro.
- Destro writes his manifesto from his prison cell. Once completed and published, he kill himself in prison.
- Rikiya Yotsubashi becomes the CEO of Detnerat, a company for personalized everyday items, and recruits various known politicians and business people into his inner circle, and they restore the Meta Liberation Army.
About 15 years before the series
- Midoriya is born.
- All Might returns to Japan, saving tons of citizens on his first night out.
- He uses what he learned in America to stylize himself as an American-themed superhero.
- At age 4, Midoriya watches his premiere on video stream, inspiring him to become a hero
- In a surprising appearance of his quirk, Shigaraki Tomura kills his family with his uncontrollable power. In his search for help, he finds All For One.
About 5 years before the series
- All Might and All for One have an epic battle, that costs them both a great deal.
- All Might requires multiple surgeries just to survive, and afterward, needs to limit his superhero activities.
- Similarly, All for One needs to rebuild himself, surviving due to his quirks in his collection. He also begins to form a plan against All Might and all he stands for.
- All Might is recommended to find a successor. After some searching, he is eventually convinced to become a teacher at U.A., both as a place for him to pass on his experience to all the students there, but also as a place to pass to find someone to inherit his powers.
- All Might and his current sidekick, Sir Nighteye, break off their partnership over irreconcilable different views on how All Might's career should proceed after his surgeries and after Nighteye predicted his death within 6 years.
Unknown time before the start of the series
- U.A. is founded.
Midoriya meets All Might
- Entrance Exam Arc
- Midoriya spends 10 months of intense training, ending with eating All Might's Hair.
- February 26: Midoriya eats All Might's hair, gaining One For All. Several hours later he takes the U.A. Entrance Exam, meeting Uraraka and Iida.
Midoriya enrolls in U.A.
- Quirk Apprehension Test Arc
- Battle Trail Arc
- Unforeseen Simulation Join Arc
- Sport Festival Arc
- Hero Killer Arc
- Final Exams Arc
- School Trip Arc
- Hideout Raid Arc
- Hero License Exam Arc
- Internship Arc
- Culture Festival Arc
- Pro Hero Arc
- Joint Training Arc
- Meta Liberation Army Arc
- Midoriya becomes the #1 hero in the world.