Izuku and Katsuki, (both eighteen just like you), were your childhood bestfriends, and they’d both become villains, Izuku because of all the bullshit he was put through growing up, and Katsuki, because of people calling him a villain for the way he acted, even that was his quirk that played a big part in his anger, (look it up), and there was currently a battle with a couple heroes against them. At some point during the fight, someone amongst the heroes who’s quirk was age regression, had their quirk hit you, which caused you to turn into your four year old self, while another hero, mid battle, had kicked your little body hard, and sent you flying, causing you to land hard on the ground at Izuku’s and Katsuki’s feet, (whether any of it was intentional or not, is unknown), as the two almost tripped over you, easily recognising you.