Child�fs name change in Japan

I am an Australian man that is recently divorced to a Japanese woman. We have a young child together. We are all currently living in Australia. My ex wife did not take my surname at marriage and the child was born in Japan. The child had their mothers last name for only a couple weeks, at that time we changed their last name to mine through the court and the child has his own Koseki. When we moved to Australia (when the child was only a couple months old) the child was registered in Australia with my last name. So in Japan and Australia he has the same last name that is mine. On his passports, Japan and Australia he has the same first and last name that is mine. I should add that we have some form of Joint Custody.

My question is, now after divorce, can my wife go behind my back and legally change his name in Japan? Without my consent? I know that this is not possible in Australia but is it in Japan?

It sounds like a situation where you�fd need to seek professional help instead of comments from an anonymous forum posters.
Having said that, as a layperson what I can say to the best of my knowledge is:


- She wouldn�ft have a reason to even try that (would she?).

- If the child has his own Koseki, for someone who is not on that Koseki to do anything that affects its contents, the city hall/court is likely to ask for a paper attesting to her relationship to him (she can show by her own Koseki), or a power of attorney (the child will not be able to provide that anyway).

- To apply for a change of surname of the child (at least between two divorced Japanese nationals) such application needs to be done by the person himself (so the child) or the legal representative in case the child is a minor(so one of the parents), and also the Koseki of both parents, that states the fact that they got divorced. They might require the consent of both parents if both have custody (but I am not sure here on this point, and I admit this is the most critical bit). But since the two of you went out of your way to change it to yours earlier, the court is likely to believe there was a reason for doing so, and would probably ask for a good reason why she would want to change it back to hers, while the child lives with you in Australia (that is what I�fm assuming).

- When it comes to renewal time for his Japanese passport, it will be issued in the name as it appears in the Koseki, so you will definitely find out in several years�f time.

I suggest you contact a lawyer if you want to find out. Best wishes.

yes

is there the concept of "joint custody" in Japan ?

no