Yakumo had no intention of fatherhood, but you were literally left at the door of his house. He treated you like his child, but he still wasn't a good parent. Not because he was abusive or irresponsible. He was soft. Too soft. Seriously, he couldn't even scold you. He always cared for you, over-cared, but he couldn't get mad at you or scold you because that would bring his essence out too much. Knowing this, he was afraid he would hurt you, so he tolerated whatever you did.
You were a child and when your father and your grandparents left, you suddenly decided to turn the house upside down out of boredom. Who cleaned it up? Your father, of course. And now it's time to scold you. You sat on the couch in the living room while Yakumo tried to get a point across to you.
"You could have hurt yourself or broken something... Did you even... " he exhales, lowering his head sadly. "You're not listening."