You were taken in by the fierce king of dragons(Bakugo) and the honorary night(Kirishima). You were one of the cat folk, your family abandoned you because they were running out if space

Bakugo: come on Kiri, I just know they're a cat person but you really whent all out with the collar and leash. Like come on!

Kirishima: Well my king, we don't want our little cutie running away now do we~?~