2025-10-20

Naturalization refers to a foreign national acquiring Japanese nationality. Since it means “becoming Japanese,” the procedures are complex and the screening is rigorous. Among countries worldwide, some offer relatively straightforward paths to citizenship.

What is Naturalization?

Naturalization refers to the process by which foreign nationals residing in Japan with a valid residence status acquire Japanese nationality. This requires submitting an application and necessary documents to the Regional Immigration Bureau.

Note that Japan does not recognize dual nationality. Therefore, acquiring Japanese nationality means losing your previous foreign nationality.

Japan’s Naturalization System

Japan’s naturalization system is among the strictest in the world.

First, to be granted naturalization, six requirements must be met.

・“Residence Requirement” … The applicant must have continuously maintained a residence in Japan up to the time of application.

・“Capacity Requirement” – The applicant must be at least 18 years old and considered an adult under the laws of their current nationality.

・“Good Conduct Requirement” – The applicant must have no issues with their conduct, such as tax delinquency, criminal convictions, or serious traffic violations.

・“Livelihood Requirement” – The applicant must be able to support themselves in Japan through their own assets/skills or those of relatives sharing their livelihood.

・“Prevention of Multiple Nationality Requirement” – The applicant does not currently hold another nationality, or agrees to renounce their current nationality upon acquiring Japanese nationality.
・“Constitutional Compliance Requirement” – The applicant does not plot or advocate the violent overthrow of the Constitution of Japan or the government established under it.

Furthermore, naturalization applications require submitting numerous types of certificates and documents. While the exact number varies by applicant, the total can exceed 100 pages.

After document submission, the applicant will undergo an interview with a Legal Affairs Bureau official. Questions primarily concern the applicant’s family, future life and work in Japan, and reasons for seeking Japanese nationality.

In other words, questions will cover the content of the submitted application and documents. Therefore, giving contradictory answers must be absolutely avoided.

Furthermore, if submitted documents contain errors or are incomplete, corrections or resubmissions will be required. After this screening period, a final decision is typically reached in about one year.

Thus, compared to the screening for other residence statuses, naturalization applications are difficult due to the greater effort and time required, as well as the stricter screening process.

Which countries have simpler naturalization processes?

Compared to Japan, several countries have simpler naturalization procedures. Note that abroad, the term used is not “naturalization” but rather “citizenship” or similar.

First is Mexico. After residing there for at least five years, you can apply for Mexican “citizenship.” This period is shortened to two years if you have Mexican ancestors, or if you have children or a spouse who are Mexican, or if you have contributed to Mexico in cultural, social, or academic fields. Application criteria include speaking Spanish, demonstrating an understanding of Mexican history and culture, and agreeing to renounce any other nationality upon obtaining Mexican citizenship.

To obtain Canadian citizenship, the key criterion is knowledge about Canada. Specifically, you must be able to speak English or French and pass a test on Canadian history, values, institutions, and rights.

In Ireland, the length of residence is the key factor. After living in the country for at least 4 out of 8 years, you must reside there for at least one additional year to qualify for citizenship.

Summary

Japan has established strict procedures and criteria for foreign nationals to acquire Japanese citizenship. However, in other countries, particularly those that have accepted large numbers of immigrants, obtaining “citizenship” is relatively straightforward.