Yeah I echo everyone here:
A family tree would be nice
Cousins are fair game in Japan. Let alone cousins super far in generations.
I forgot, what the deal with his mom again. She wasn't his real mom or something?
I am a big proponent of Japan needing more therapy, but I also agree that this issue may not necessarily need a licensed therapist. I think it's a combination of Aya needing to be more open and confessing her struggles, and her loved ones talking to her about her struggles. Like her mom has...