Is He a Product of Incest?

"This happened in Japan. It seems like they were all aware from what I could gather," she says of her husband's family. "I don't know if his younger siblings knew because he would end up having more kids with his wife and producing, well, I'd hope so." He has a couple older sisters, yeah. They are like of age. That's possibly... We don't even know their ages from what I can find.