Child-rearing is difficult even for heterosexual married/ unmarried couples. The genders of the parents does not define proper parents but their children's life; how they act and perceive things that are presented to them through their senses. And I believe that Ai and Nao were great parents since Hiro grew as a happy and endearing child. He does not let his differences become insecurities but uniqueness. I love this! It's so wholesome!
Boku no Papa to Papa no Hanashi