Responses
I know this is an old comment and you probably don't care, but hair do be that way sometimes. My parents have blonde hair (mom) and black hair (dad). My oldest brother has black hair, my next brother has sandy, dirty blonde, my third brother has mud brown, and I have red hair. So yeah, we all have different color hair. It happens. Genetics come from more than just mom and dad.
I agree that this can happen, but it's not so common that it happens in all the families. Especially, when this work is from countries with predominantly black hair.
Another example of illogical physical attributes like Heat and Run.
Aki has light hair and his brother has dark hair. And Sai's family.. Every single one of the brothers have a different hair color. Like.. Just why and how..
My only consolation is that the author here (unlike in Heat and Run) did not make him (Aki) light haired just to make him uke. Averted Light haired uke stereotype successfully. Thanks Author.
Enjoyed reading this though.