renounce citizenship ?

in order to get japanisse citizenship you have to renounce any other citizenship?

Yes:
http://www.japan-guide.com/e/e2221.html

Alexia,

Actually, I think you will find that the answer is no. While Japan does not officially recognize dual citizenship, renouncing your previous citizenship is not a requirement for obtaining Japanese citizenship.

Japanese law states that people seeking Japanese naturalization have "no nationality, or the acquisition of Japanese nationality will result in the loss of foreign nationality".

But since some other countries, notably the US, do not recognise the renunciation of citizenship, it becomes impossible to do so even if you try. Even so, some Americans have become Japanese citizens. So the answer is probably "in theory, yes, in practice, no".

Japan does recognize dual citizenship up to age 22 if you were born with dual nationalities. After 22 they will only recognize whichever one you choose.
Say you choose Japanese, even though it says you have to renounce your other citizenship, theres no checks and balances system. There are many people who just hold onto their former passports, they just never show or use them in Japan.

But since some other countries, notably the US, do not recognise the renunciation of citizenship,
You can renounce your US citizenship by filling out paperwork, after its approved you will no longer be a US national. Nothing notable about it. I'm sure other nations have a similar process.

Oops, I quoted what I have read elsewhere, but it seems my source was incorrect. John is right.

Yes, you can renounce your American citizenship, but you can also state that you are being compelled to do so against your own desires and intentions, in which case you will not actually lose your citizenship. Also, even in cases where Americans have willingly renounced citizenship some have successfully had citizenship reinstated.

I would not seek answers to questions such as these on an online forum, but rather from qualified professionals.

http://travel.state.gov/law/citizenship/citizenship_776.html

If you did it "under arrest" I'm sure it could be null and void.

But in most other cases in most times once you renounce the only way to get it back is to go through the entire US immigration process over again.

Notwithstanding I'm not even sure if the OP is a US citizen. Canada has a similar process. I think Britain etc does as well.

re the last post: Canada allow multiple citizenship. Some people have 3 or more!!!. Note than the European union has dual citizenship of a sort too: the native country plus the European union. I was born in Europe and have kept my original citizenship after becoming a Canadian citizen. I don't have an ID card or current passport from my native country, simply because it is too expensive to keep renewing them. The consulate of my native country gave me a special card to prove that I am still a citizen (apparently one could loose the citizenship if one had no official dealings with that native country for 30 years!) The Consulate staff know that I am a Canadian citizen and it is OK with them (many of the consulate staff themselves have dual or even multiple citizenship).I am even allowed to vote in some elections.

"Loss of U.S. Citizenship
The automatic acquisition or retention of a foreign nationality does not affect U.S. citizenship; however, the acquisition of a foreign nationality upon one's own application may cause loss of U.S. citizenship under Section 349(a)(1) of the Immigration and Naturalization Act (8 U.S.C. 1481). In order for loss of nationality to occur under Section 349(a)(1), it must be established that the naturalization was obtained with the intention of relinquishing U.S. citizenship. Such an intention may be shown by a person's statements or conduct. If the U.S. Government is unable to prove that the person had such an intention when applying for and obtaining the foreign citizenship, the person will have both nationalities."

Here is the source:
http://japan.usembassy.gov/e/acs/tacs-7118.html

Red frog, I'm NOT talking about the US or Canada recognizing dual citizenship.

I'm talking about how one can renounce their citizenship for either country. Not that either country doesn't recognize dual citizenship.

In fact here is the form to renounce Canadian Citizenship:
http://www.cic.gc.ca/EnGLIsh/pdf/kits/citizen/CIT0302E.pdf

John, please accept my apologies for misunderstanding your post. I am truly RED FACED about it.

thanks all of you for your answers