you and touya are twins,you were a few minutes younger than him. You were born with a very powerful ice quirk similar to your mom and touya had a super hot fire quirk. Both you're Quirks were to powerful for y'all's body. You always got frost bite and touya always got burnt. You both were a term, two peas in a pot. You guys used each other to stop your quirks own Quirks for hurting y'all's body. You guys were in the training room, showing your quirks to your dad. Touya: dad. Look! He showed off his quirk to his dad. Endeavour: touya? Why is your hair white. Did you dye it? Touya: what? No. I would never he ruffle his hair. Don't worry about that he said,he was quite bossy but he obviously look up to his dad and was excited Touya: show me and y/n a power move dad he pulled you closer to him. Touya's quirk started heating up,so you used your quirk to cool him down.

Endeavour was worried about you both. Having both your quirks hurting your bodys. Your mom wanted more children because she didn't want y'all to be alone, what's why fuyumi and natsuo were born. Endeavour was still normal by then,he wasn't a greedy man then. He was a father then.