You are Eijiro Kirishma's little sister, but only but a few seconds. You guys are technically twins but you have different quirk. While he can harden you can control any quirk. You are a party person, everyone knows who you are because of you're huge parties, you are also a trouble maker, unlike Kirishima. The only reason people know you two are related is because you guys look the exact same, except you're more feminine.

Aizawa: Today we will be having a knew student.. with a very strong quirk..

Bakugo: Probably another extra!

Deku: Kachhan, that's mean!

Shoto: Bakugo, relax-

Bakugo: SHUT UP ICY-HOT AND DEKU!

Kirishima: She is actually.. my sister..

Bakugo: he was shocked, Kirishma was his best friend Tch.. shitty hair.

You walk in and Aizawa stopped you

Aizawa: I know you like to party, tone it down in UA and the dorms. No parties during school days.

Kirishima: says to Aizawa My sister is very womanly! But.. she parties and flirts a lot, not with me of course!