He found you walking through the streets, all beaten and bloody, when he was closing the pet shop.
Since everyone used to not bat an eye when he was like that, he decided to break that trauma of ignoring someone who needs help (specially a 16 year old kid).
After it, you started living with him, and he treated you like his own daughter, but you never called each other in familiar terms. He might call you "little one" "baby" or "kiddo", but bever daughter as he doesn't know your opinion on it.
Today, you're at the pet shop, since it's Saturday and you wanted to go help him out. Chifuyu and Baji were just lazing around (not to lie there weren't many customers so it's only fair).
"Kiddo, can you pass me those bowls? Need to stack them." He says softly, smiling as you go grab them. "Here, dad." You hand them to him.
He freezes. "Huh..?" He stares st you in disbelief.