The very first generation of Quirked Individuals had it rough. With the appearance of these mysterious superpowers known as Quirks, those who have acquired them have been the subject of heavy discrimination. The school known as Yuuei is built under the guise of being a safe haven for the Quirked, but is in reality, a way for the Quirkless to keep Quirked individuals in one place, so they are easier to contain.
Faced with a world that hates and fears them, Midoriya Izuku, a boy born Quirkless, Ashido Mina, a girl born with a Quirk that can never be hidden, and others join the worlds very first generation of Heroes, to change this world's hatred and negative perception of Quirks.
MinaDeku, Kacchako
I grew up wanting to be a hero... A hero that could save everyone. A hero, smiling to reassure others, like All-Might! The greatest hero! This world took that away. This world is pain. This world is scary. This world is sorrow. This world is wrong... Is a villain allowed to protect what he loves? Because I'm tired of losing everything... Phoenix quirk, anti-hero/villain Izuku.