Responses

That's typically how divorces in Japan work. If the mother is remarrying the children will be removed from the biological father's family register, and placed on the step-father's family register. The bio-dad typically has 0 rights to his children after divorce, and it's not uncommon for them to only meet a handful of times after the divorce, depending on how hard he pushes to see his children. My friend has only seen her dad like 3 times in the 15 years her parents have been divorced
Loved this, but I wish there was a sequel to make Saya happier - I wouldn't even care for the yaoi, just give that man someone to appreciate him!!
In a side note, this is a very common trope on mangas - once the parents divorce, the child will stay close/in contact with only one of them. I find this so weird... your marriage is over alright, but not your parenthood. Even worse is that Saya wished to still maintain contact with his children, and that contact doesn't need to necessarily have a bad effect on the mom's new family. Just so frustrating.