>>49409977No in-universe explanation other than hair being a great indicator character design-wise that two characters are related. Some cases don't count like Peony and his daughter or Marnie and Piers. In this case, you're supposed to point at your screen and go "WOW IT LOOKS JUST LIKE OTHER CHARACTER I KNOW". No need to overthink it.
However I'm going to overthink it:
>possible genetic predisposition in personality to style hair in a certain way>hair grows and takes shape the way it does on a genetic level (if your parent has an obvious weird-looking cowlick then you will until too unless you cut and style your hair)>PLA doesn't even take place in the past, it's all a stage play and/or movie done by trainers/their relatives in the modern day>none of them are related and every single one of these are a complete and utter coincidence 
