Search Terms: Child registration (Japan), childbirth (Japan), single parents child registration
My main character (Japanese, male) has taken in a three-months-old baby who comes from a different dimension and isn't human (but can pass for human). The child's birth parents are dead, and no one was willing to take care of the baby, so he and his partner (who also isn't human, and can't pass for human either) decided to take her in and raise her as their child.
I'm assuming that he should try to register the child at some point. My problem is, how would he explain her presence? The existence of non-humans isn't common knowledge, so he can't reveal that. However, saying that he just adopted her without going through the legal process would raise all kinds of questions as well. My angle is to have him claim that she's the result of a one-night-stand and that the mother didn't want to raise the child, but since there is no birth mother actually involved, he has no proof for that.
If all else fails, I can have friends of the main character forge the required legal documents, but if at all possible, I would like to find a legal way.
Thanks in advance!
ETA: The most obvious way in which the non-humanness of the child manifests is that she isn't visible or tangible outside her native dimension. Both MC and his partner have the power to keep her visible/tangible in other worlds, but if she's taken away from them, however briefly, it will look like she just disappeared, so I really want to avoid that scenario.