After marriage in Japan change to double name

Hi, my japanese wife and me married in Japan. After that we registered our marriage in my home country. We both kept our own last names. We would like to change my wife's last name into a double name.
I can change her last name in my country without any problems, however authorities in my country told me that it's best to change the last name in Japan too into a double name since she probably won't get a japanese passport with a double name then and that there will be problems then.

I've seen a lot japanese who are married with foreigners and have a double name, where in Japan do I have the possibility to change that? Maybe someone here knows about that.

As far as I know, the Japanese spouse could file an application with the family court in Japan to change her family name to yours, but no hyphenated name is used in Japan. (Please check if this has been changed more recently.) And there is no middle name either.

In my case (Japanese, married to a continental European), upon marriage I kept my family name, but there is a way to have the husband�fs family name shown in parenthesis on my passport, so that�fs what I have to be able to show that we are married.

So if my name is Hanako Yamada, it still is �gHanako Yamada�h on my Japanese koseki (family register) and juminhyo (resident record) officially, but only on my passport it appears as:
Hanako Yamada (Smith).

I buy air tickets with just �gHanako Yamada,�h so this name on passport is simply to show the spouse�fs family name and that I am married.

"double name" means a hyphenated name? Like, Smith-Suzuki or Suzuki-Smith?

Hmm.

I've never met a Japanese person who has a double name like that here in Japan. If you know some though, why not ask them directly how they did it? I can tell you that it is a PITA to have a long/non-kanji/unusual name here, though. If she does go through with it, I'd recommend registering her maiden name as an alias so she can use that instead of the double name for most things.

Anyway, when two Japanese people marry, they have to have matching last names. However that's not the case for a Japanese and foreigner's marriage; since Japan doesn't have the legal ability to change the name of a foreign national, they don't have to match. I would think the easiest course of action would be to get your own name changed first in your home country, then bring that new name and documentation of it to city hall, show that you're married, and ask to change your spouse's name to match. You should probably also check with them ahead of time about a name that is hyphenated versus not hyphenated (Suzuki-Smith vs. Suzuki Smith) and how that's handled, or what the procedure would be. In fact, city hall is a great place to ask first regardless! So I'd start there.

Worst case, you might have to go to family court to get a judge to hear your case and allow you to change your name. But I feel like there is probably an easier way!

the above two posts are mostly correct.
even when she ADD your name, (like maiden name), on her passport, her legal name is still in being maintained. so, adding your name on her passport is just for self-satisfaction of you and her.
about alias, I believe that system is for foreigners. probably, very unlikely for Japanese. but, need confirmation.

It's not possible for a Japanese to have two surnames lawfully registered in Japan, but it's now become very easy to change a Japanese national's surname to her husband's. As she registers her marriage at the city hall, usually, all she has to do is to go to the next counter and have simple paperwork done. I wonder if your "double surname" can be considered as "one surname" which will allow you to do what you want.

Another thing is that, as mentioned, it is possible to have a different surname shown in brackets on his/her passport. So for example, your wife can change to your surname, and have her maiden name indicated in brackets. See below for details:
https://www.mofa.go.jp/ca/pss/page3e_001033.html

Also note that it is now easy for any person to have his/her former surname indicated at the side of his/her juuminhyo, inkantourokusho, My Number Card and driver's license. (System was changed last Nov-Dec.) You can find out how by checking your municipal's official website. The following is just for reference.
https://www.soumu.go.jp/main_content/000625550.pdf
https://www.npa.go.jp/bureau/traffic/menkyo/maiden_name/maiden_name_jp...

As mentioned, just because you don't have your other surname indicated on official papers, that doesn't necessarily mean that it would lead to complications. But especially when you've just changed your name, being able to carry around the proof of your history can be handy.

"The Civil Code and the Family Register Law require the use of a single surname by members of the same family."
Possibly you can select a new name for the both of you, but normally you pick one family name or the other.
https://www.japantimes.co.jp/news/2020/01/28/national/politics-diploma...

JapanCustomTours,
The above rule you quoted applies only to Japanese-Japanese couples.