Honoka K?saka loves her school. That's why it's bad news for her when she finds out it's being shut down due to lack of new students. In order to bring in more students, Honoka decides to start a "school idol group," which is certain to get the eyes of the public. To make this dream a reality, she gathers together her close friends and classmates to make the best idol unit possible.
Mankind has developed superpowers known as "Quirks" with 80% of the population having some kind of superpower. These new abilities see the rise of both superheroes and villains. A prestigious school known as the The Hero Academy trains superpowered hopefuls into the heroes the world needs. Middle school student Izuku Midoriya wants to be a hero more than anything, but he's part the 20% without a Quirk. Unwilling to give up his dream, he plans to take the exam and be accepted into a high school for budding heroes. Through a series of serendipitous events, he catches the eye of the greatest hero, All Might, who agrees to train him.
There is a new team of "Toei robot girls" named "Team Z" that is made up of three girls based on Toei's Mazinger Z franchise: Mazinger Z, Great Mazinger, and UFO Robot Grendizer. Usually they perform in activities around Nerima ward in Tokyo to raise the awareness of the promising future energy source "Photon Power". However, there are times when "Mechanical Beast" team of girls emerge from the "Subterranean Empire" and attempt to steal the energy. Thus "Team Z" has to battle them to prevent this, though sometimes they just go and beat up the "bad girls" to relieve stress.