In the event you (Assume that you were born outside of Japan. You do not have Japanese relative) want to obtain Japanese citizenship, it may be better to know information below.
In order to be Japanese national, you need to satisfy several requirements.
1 You have lived in Japan for five years or more consecutively.
Even if you live in Japan for 5 years or more (assumed 1, January 2000 ～ 1, January 2005), if you have not lived in Japan for 3 months during such 5 years (assumed from 1, January 2003 ～ 1, April 2003) , you can not use period of prior to 1, January 2003.
Or if you have not lived in Japan for 100 or more per a year, you will deemed that you have not lived in Japan for five years or more consecutively.
And even if you have lived in Japan for five years or more consecutively, you need to have status of residence that allow you to work in Japan for 3 years or more.
Minor can apply for naturalization as far as she applies for it with her parents.
You also need to have paid tax, pension in Japan.
If you have not paid tax as of now, you can pay it now and make application.
(even if your spouse does not pay tax, you can not obtain citizenship).
In the case you have applied for dependents deduction using your relatives, if the dependents are not qualified to become your dependents, you need to modify it and pay additional tax.
In the case you apply for naturalization, you need to provide many documents that clarify your relatives in your home country.
So, if there are some mistakes, it should be problem.
If you have not paid pension, you need to pay it (at least for one year ) before your application for citizenship.
If you have criminal record (including severe traffic related violation), you can not obtain citizenship.
You need to have stable job in Japan. Though, you need to prove soft copy of your bank book, the amount of your asset is not important.
By the bank book, you need to clarify that you have stable income (more than 200,000 yen per a month).
Once you have obtained Japanese citizenship, you need to lose your original citizenship.
You need to have basic Japanese language skill (more than Nihongo nouryoku kensa 3 kyuu).
In the event your spouse is not Japanese national, you can apply for naturalization without your spouse’s naturalization.
(If your spouse is Japanese national, you can apply for “easy naturalization”. Requirement mentioned above can be eased )
Outline of this process
You can talk with a person of authority and you will receive information of necessary documents for application for naturalization.
About 2 or 3 months after your application, you will have interview with officer.
If you have spouse, your spouse will be also requested to come with you.
And there are possibilities that officer will come to your house to confirm situation.
And there are possibilities that officer will contact with your working place and parents house of your husband (if he/she is Japanese national.
If your application is granted, your name is published in official gazette.
(at the time you apply for naturalization, you need to determine name of after naturalization. You can not use alphabet, nor middle name)
It will take about 10 months ～ 1 year from application to completion.
Necessary documents for application for naturalization.
Certificate relating to tax payment
Certificate of residence
Certified copy of real estate registry
Certified copy of commercial registry (if you or your spouse operates company)
Certificate relating to Pension payment
Withholding tax slip
Driving record for past five years
Tax return paper
Birth certificate (all relatives)
Many other documents are also required.