2025-10-07

“Naturalization” refers to a foreign national acquiring Japanese citizenship. Can someone who has naturalized—that is, become a Japanese citizen—revert to their original foreign nationality for some reason? Let us explain in detail.

What is Naturalization?

“Naturalization” refers to a foreigner holding a residence status in Japan acquiring Japanese nationality. To do so, they must submit an application and required documents to the Legal Affairs Bureau and undergo screening.

Note that Japan does not recognize “dual nationality.” Therefore, if granted Japanese nationality, the previous foreign nationality is lost, and the individual holds only Japanese nationality.

Can you regain your original nationality after naturalization?

Can a foreigner regain their original nationality after naturalizing in Japan (acquiring Japanese nationality)?

The answer is: “Whether you can regain it depends on your original foreign nationality.” If the laws of the country you wish to return to permit the restoration of nationality, you can regain it. However, if the laws of that country do not permit nationality restoration, you cannot regain it.

China’s “Article 16 of the Nationality Law” stipulates: “Applications for naturalization, renunciation, or restoration of nationality of the People’s Republic of China shall be reviewed and approved by the Ministry of Public Security of the People’s Republic of China. Upon approval, the Ministry of Public Security shall issue a certificate.” This means that in China, the Ministry of Public Security handles the review and approval for restoring nationality (reacquiring Chinese nationality).

South Korea also has procedures for nationality restoration. Specifically, one must complete the “Acquisition through Nationality Restoration” procedure at the South Korean embassy.

As outlined above, many countries permit restoration of original nationality after acquiring Japanese nationality. To confirm whether such procedures exist in your home country, you must verify with your home government or embassy.

Can one naturalize again?

So, can a foreigner who has naturalized in Japan return to their original nationality and then subsequently acquire Japanese nationality again?

The naturalization application process involves reviewing the requirements for acquiring Japanese nationality and granting permission if those requirements are met. Even if you previously held Japanese nationality, at the time of the naturalization application, you are no longer Japanese but already a foreign national. Therefore, the process is the same as a standard naturalization application. Consequently, re-naturalization, meaning reacquiring Japanese nationality, is possible under the system.

However, it is reasonable to assume that the applicant’s circumstances may differ between the first and second naturalization applications. Therefore, having been granted naturalization in the past does not necessarily mean the hurdle for the next application is lower or even the same.

Summary

Whether one can revert to their previous nationality after naturalization depends on whether the laws of their home country include provisions for “reacquisition of nationality.” Furthermore, while the system permits a foreign national who has reacquired their original nationality to apply for naturalization again, this does not necessarily mean the naturalization will be granted more easily.