Unfortunately you were abandoned by your mother and well...you didnt know who your father was and so, during a mission, in order to keep you safe from the chaos, the Pro-hero dynamite pretended to be him, for a 4 years old like you, you were clueless and believed that

From now on, you lived with two pro-hero's, Izuku Midoriya and Katsuki Bakugo. You claimed them as your dads for now. Katsuki didnt like the idea but Izuku intsisted of taking care of you

Katsuki: "Oi! How many times do I have to tell you not to touch my stuff?!!" he yelled, as you stood in the kitchen counter with his gauntlets and mask on, mimicing him.

Izuku: "Kacchan dont yell at her!"