Quirks are the equivalent of superpowers and are considered the next natural step in evolution. Quirks can vary in strength and utility. Some quirks emit various materials or substances like fire and ice, which is the quirk of Shōto Todoroki. Other quirks may involve strange mutations such as Mina Ashido, who has pink skin, antenna, and emits some form of an acidic substance form her skin. In the case of Izuku Midoriya, who was gifted his quirk from All-Might, he has an enhancement-based quirk that provides him incredible strength and speed.

However, every great quirk, such as the ones Todoroki and Midoriya possess, also bring unique set-backs or weaknesses. In the case of Todoroki, who tends to favor his ice side more than his fireside, if he were to overuse his ice side, he begins to freeze over half of his body and overexert himself. Midoriya’s quirk is one of pure power, one that he was not born with and must grow accustomed to and control. Without proper control and training, it can result in broken bones, bruising, and other severe forms of injuries as Midoriya is utilizing a quirk beyond his physical capabilities.

In this alternative world, quirks are not a brand-new concept, they have been around for long enough that society itself has evolved to accommodate a super-powered civilization. In particular, police forces are trained to handle quirk-related crimes. There has also been the establishment of registered heroes and hero agencies. Heroes like All-Might and Endeavour are recognized by the government and carry out superhero-related activities and missions. Many heroes work for or have their own hero agency that represents heroes and hires students straight out of school to become sidekicks.

In the world of quirks, one is not born a hero but must train to become one. This is done at various schools specialized in training the next generation of heroes. The number 1 ranked school for this task is U.A. High School with top-notch teachers such as All-Might, Eraser Head, and Present Mic leading different classes. Class 1-A and 1-B make up the group of students enrolled in the heroics arm of U.A. High School’s academics. Not everyone can be a hero as the exams for entry are incredibly competitive and not everyone may want to be one. For this reason, there is also a general education stream where students learn everything one would expect to learn at a high school level to prepare them for the workforce or college. There is also a business stream to develop skills in various ventures involving heroes that require proper business acumen. Finally, there is the support stream for those who are interested in learning to develop the technology that supports heroes in their line of work. From the suits, they wear to the equipment they use.

The greatest rival to Izuku Midoriya is Katsuki Bakugo. Bakugo was a childhood friend of Midoriya, however, after he uncovered his quirk which allowed him to create explosive blasts, he began bullying others who never developed a quirk, including Midoriya. While Midoriya did not wish to fight with Bakugo, Bakugo would consistently look down on him. Bakugo became enraged when he discovered Midoriya had obtained a brand-new quirk that seemed to surpass his own in some respect. Tensions increase between the two at UA High School as Bakugo looks to surpass everyone and become the best hero.

Tomura Shigaraki is the leader of the League of Villains, an underground organization of anarchic supervillains who want to see the hero-centric society around them crumble. Shigaraki has a particular obsession with All-Might. He views All-Might as the representation of all that is wrong with society and its focus on heroism and he wants to see All-Might destroyed as a result.