2025-09-18

Suppose a former Japanese citizen who lost Japanese nationality and acquired foreign nationality wishes to regain Japanese nationality for certain reasons. Is this possible? What procedures are required? While quite rare, we will explain.

What is a Naturalization Application?

The process by which a foreign national acquires Japanese nationality is called a “naturalization application.”

A naturalization application involves a foreign national submitting an application form and supporting documents to the Legal Affairs Bureau (Immigration Services Agency) with the aim of acquiring Japanese nationality. Ultimately, the Minister of Justice grants permission to acquire Japanese nationality.

Upon approval of the naturalization application, the applicant loses their previous foreign nationality and becomes a Japanese citizen. Consequently, the screening process involves strict requirements. For example, the applicant must be of legal age (18 years old) under Japanese law. They must also be of legal age under the laws of their current country of nationality. Other requirements include having paid taxes properly during their period of residence in Japan and having no record of serious criminal penalties.

How Former Japanese Citizens Apply for Naturalization

First, former Japanese citizens need a Japanese address to apply for naturalization. Therefore, they must have a Japanese residence certificate (Jūminhyō). To obtain this certificate, they must stay in Japan with a mid-to-long-term residence status valid for at least three months.

Former Japanese nationals whose parents hold Japanese nationality can obtain the “Spouse or Child of a Japanese National” residence status as the biological child of a Japanese national. When applying, the applicant must attach a copy of the parent’s family register (koseki tohon) listing them as the “child.” If both parents are deceased, a copy of the family register extract (jokei tohon) serves as a substitute.

Next, a foundation for life in Japan is required. This includes proof of employment sufficient to support oneself in Japan, bank account balances, etc. A guarantor is also necessary. Typically, a relative such as a parent is asked to serve as the guarantor.

There are three methods for entering Japan from overseas:

・Have the applicant’s parent or relative obtain a Certificate of Eligibility (COE).

・Enter on a short-term stay visa, obtain a COE, and change your visa status.
・Enter on a short-term stay visa and change your status from short-term stay to a spouse visa.

Important Notes

Former Japanese nationals who have acquired foreign nationality are not subject to relaxed naturalization application screening simply because they were once Japanese. They must submit the same application form and supporting documents required of general foreign nationals applying for naturalization. The screening period also typically takes about one year.

Furthermore, as with standard naturalization applications, a statement of motivation for naturalization, an essay, and possibly an interview are required. No special exceptions are granted simply because the applicant was formerly Japanese.

Summary

Former Japanese nationals who have acquired foreign nationality and wish to regain Japanese nationality must apply for naturalization, just like other foreign nationals. Furthermore, the screening process is not relaxed simply because the applicant was formerly Japanese; it proceeds according to the standard naturalization application procedures.