@xp32 - INCORRECT, XX/XY is what decides sex, while sexual orientation is based on gender. So since one identifies as a man and one identifies as a woman, they are both straight,
OR
attraction is based on feminine or masculine characteristics in which one of them is being lesbian, and the other is being gay
The story's been slugging since the little sister's been introduced. I'm more than willing to wait but man do I miss every chapter having romantic development between the main two.
@TrumanHanson117 On gender expression alone I'd call it a queer relationship rather than straight, because it's so far from the spirit of the word 'straight'.
Labels break down at a certain point so it's easier to just note it's not a usual straight couple, and to not mind nuances like Japanese pronouns and gender identity.