legal last name change-koseki

Greetings all and hajime mashite

I know this may have been posted before but i like to clarify certain matter in regards to name change.
Scenario
I am Singaporean and married to my wife who is japanese. We had decided to change our names to include both our last names rather than take on any side.
For EG. ALAN SATO (last name of wife )LEE (last name of me)
how shall we go about doing this aside form the trouble of getting all the documentation renamed in our country of origin which doesnt really matter to us. As both of us are working overseas currently.
We are planning to do this as our passport and work visa is due for renewal in the country where we are working.
Can any one kind enough to give me some advise and guide us through the right channel.

Secondly.
We got married in singapore and is legally registered in singapore.
We are planning to head back to japan in a few days to report this to the japanese government.
- What documentation will i require aside form the marriage certificate translated and passport. Do i require the proof (non impediment if i can recalled) that i wasnt married before as this was already done in singapore when we got married.

Thirdly
I am planning to apply my spouse visa as we are moving back to japan later this year.
How can it be done?

thanks for reading. should you be able to direct us to the relevant authority when we are in tokyo, my spouse - place of origin.. that will be great

arigato gozaimasu,
Alan

1. Name change.
Both of you need to go through own country authority for name changes.
FYI for Japanese, any name changes related to marriage can be done within 6 months easily, after that it
will involve visit/procedure to court.

2. CNI is not required as you already married/registered in Singapore. CNI is only need when you want to get married and register in Japan.
You will need marriage cert from Spore though for Spouse Visa application. Instead of reporting/registering your marriage in Japan, you can register/notify it at Japanese embassy in Spore.

3. Spouse visa -
2 ways of doing it, either COE or Change of Status way.
i. COE-Visa (You'll be separated from your wife)
Your wife need to apply for COE at immigration office in Japan.
Once approved, the COE will be send to you in Spore which then you need to bring COE, related
documents and application for Spouse visa at Japanese Embassy in Spore.
Once your visa approved, visa stamped on your passport, you can now enter Japan with stamped
visa passport & COE, and given resident card(zairyu card) which confirm your resident status as
Spouse of Japanese National.

ii. Change of Status (everything done in Japan, you get to stay with your wife)
You enter Japan as temporary visitor (Spore visa waiver?).
Have all relevant document ready, go to immigration and make application for Change of Status from
Temporary to Spouse of Japanese National. While your application being process you can stay with
your wife until the application decision is made.


https://www.sg.emb-japan.go.jp/itpr_en/visa_documents.html
https://www.mofa.go.jp/j_info/visit/visa/long/visa10.html

Addition

1. Good read on name changing after marriage.
https://www.reddit.com/r/japanlife/search?q=name%20change&restrict_sr=...

3.Spouse visa application
i. COE
English
http://www.immi-moj.go.jp/english/tetuduki/kanri/shyorui/01.html
Japanese
http://www.moj.go.jp/ONLINE/IMMIGRATION/ZAIRYU_NINTEI/zairyu_nintei1.h...


ii. Change of Status
English
http://www.immi-moj.go.jp/english/tetuduki/kanri/shyorui/02.html
Japanese
http://www.moj.go.jp/ONLINE/IMMIGRATION/ZAIRYU_HENKO/zairyu_henko1.htm...

I may be wrong on this, but I seem to recall that the surname of a Japanese (your wife in this case) must be a Japanese name. I don't think she can become a 'Lee' on her koseki.

Not really. My wife took my surname.



In case of international marriage, Japanese spouse (wife) will create her own separate family register/koseki and become the household head.

As for the name, the wife can either continue using her current surname or change it to husband surname. Grace period of 6 months is given to change name easily, after that it will involve court order legality.

Foreigner husband can decide whether to adopt wife surname or not but it won't matter to Japanese government. Any name changes on foreigner husband is to done/dealt with husband country authority.
Foreigner husband will be recorded into Japanese wife koseki.

Note that while in Japan, child born will be register in Japanese wife koseki, will adopt whatever surname that wife had chosen.

As far as I know:

1. Your name changes need to be registered with your respective home country – meaning, only Japan is the authorities with which she can officially have her family name changed (to be reflected into her passport), and Singapore is the only authorities where you can have your Singaporean name changed officially.
Before you actually apply, I would check if both countries allow double names, or if only one is allowed, or one hyphenated name would be allowed, possibly.

2. That is all (marriage certificate, its translation, and passports as ID), as far as my experience goes, but be sure to check with the city hall where you plan to report the marriage. (No CNI needed, as that was for you to get married.)