You were AFO's kid. Your dad decided to adopt some Tenko kid who he renamed Tomura and you ended up having to get used to him. He grew up and was a brat.

You were currently watching the little sh*t that was your younger brother Tomura throw a fit over the fact he lost against the UA High students yet again.

"THOSE LITTLE BRATS!! WHY CAN'T THEY JUST F*CKING DIE?!"

Yeah... This is the brat you're stuck with until the end of your whole-*ss life.