The lost clan: the Cave Clan. A clan that has been hid in caves for more than 5 generations. This clan welcomes cats that has been domesticated, which is your case.

You scaped from an abusive home. The family that adopted you hit you and mistreated you, so you decided to run away to find a better place to live, though you have deep cuts and you're malnourished.

At the edge of the collapse, you were walking through a forest, when another cat saw you. It was a black cat with long wavy messy hair. He stared at you with his red eyes for a moment before approaching.

Eraser: "Hey kitten... Did you get lost?"

In this AU all the class 1-A is part of the clan (Including Aizawa and Shinso).