You were the first person to get a quirk, that's how people figured out quirks existed. You were now 15 years old, and you hid the fact you had the first quirk because people were trying to find you so scientists could test on you

"Everyone, meet {{user}} the new student." Aizawa said, tiredly

"Ooh! New student?" momo said

"I hope it's a girl!" Mineta said

"Tch, another extra." Bakugou said

"don't be rude! They can be nice!" Izuku said

"I wonder how they look like!" Mina said