The appearance of "quirks," newly discovered super powers, has been steadily increasing over the years, with 80 percent of humanity possessing various abilities from manipulation of elements to shapeshifting. This leaves the remainder of the world completely powerless, and Izuku Midoriya is one such individual. Since he was a child, the ambitious middle schooler has wanted nothing more than to be a hero. Izuku's unfair fate leaves him admiring heroes and taking notes on them whenever he can. But it seems that his persistence has borne some fruit: Izuku meets the number one hero and his personal idol, All Might. All Might's quirk is a unique ability that can be inherited, and he has chosen Izuku to be his successor! Enduring many months of grueling training, Izuku enrolls in UA High, a prestigious high school famous for its excellent hero training program, and this year's freshmen look especially promising. With his bizarre but talented classmates and the looming threat of a villainous organization, Izuku will soon learn what it really means to be a hero.

Takane Takamine is great at everything she does, and her magnetic personality makes her the envy of everyone. She gets good grades, excels at sports, and even manages to become student council president during her first year of high school. But Takamine has a secret—she possesses an ability called "Eternal Virgin Road," allowing her to redo past actions and achieve a different result. While this might seem like a decent skill to have, Takamine must pay a price to activate it: she has to strip off a piece of her lingerie. After getting an imperfect score on a test, Takamine begins to remove her underwear during class and is spotted by her average and weak-willed classmate Koushi Shirota, who is bewildered by the sight. However, the very next instant, things reset and Takamine's test is now perfect. When Shirota decides to confront Takamine about her previous test score, she reveals her ability to him and blackmails him into becoming her "closet," making him carry around extra lingerie and put them on her. Her goal is to be able to use Eternal Virgin Road as much as possible in order to stay at the top of the school hierarchy. Left with little choice in the matter, Shirota accepts, starting an oddly intimate type of relationship with the most popular girl at school.

The inhabitants of a certain wealthy town think nothing of throwing objects away. However, their waste is priceless to Rudo, a resident of the town's slums. Despite the constant warnings from his adoptive father Regto, Rudo spends his days searching for reusable materials that would otherwise be sent to the giant disposal area known as the Pit. Due to its vastness, the Pit doubles as a means of criminal punishment; those dropped in are never to return again. When Regto is murdered by a mysterious assailant, Rudo is falsely accused of the crime and thrown into the Pit. To his surprise, he awakens in a trash-filled area inhabited by enormous monsters formed from the junk. As the toxic air and Trash Beasts push Rudo to the brink of death, he is saved by Enjin, one of the Cleaners who wield weapons known as Vital Instruments to fight the monstrosities. Having gained his own Vital Instrument, Rudo soon joins the Cleaners in the hopes of finding a way to escape the Pit and avenge his father.

Next to Miyu Suzuki, a trendy and bubbly high school girl, sits Yuusuke Tani, a quiet and frank boy. Their interactions are brief, limited to Suzuki's unprompted random questions and Tani's succinct answers. Yet, beneath these simple exchanges, feelings of love are quietly blossoming. Suzuki sees Tani for who he is: a straightforward boy who respects everyone equally, completely unconcerned about fitting in. Unlike Tani, she is too hung up on what everyone else thinks, desperate to keep her crush a secret. However, a slight misunderstanding leads to Suzuki confessing her feelings—and to her delight, Tani feels the same. Jittery with excitement, the young couple starts dating, embarking on a wonderful journey of friendship and love.