Japan’s Naturalisation Requirements Effectively Extended to “10 Years”Key Points Explained for Foreign Residents

Following the 2024 legal developments, Japan’s naturalisation system has reached a significant turning point.

In particular, attention should be drawn to the stricter administrative practices that came into effect on 1 April 2026.

In this article, we explain in detail what has changed and what will now be required for applications, from the perspective of an Administrative Lawyer supporting foreign residents in the Shiga and Kyoto regions.

What Does the “Tightening” of Naturalisation Screening Mean?

Major Changes from April 2026

From 1 April 2026, the practical standards applied in naturalisation screening have been significantly raised.

The most notable change concerns the residency requirement.

Although the Nationality Act still states that applicants must have resided in Japan for “five years or more”, in practice this has now shifted to “approximately ten years as a general rule.”

This does not simply refer to the length of time one has lived in Japan. Rather, it reflects a stricter assessment of how the applicant has contributed to and integrated into Japanese society during that period.

Why Has the Residency Requirement Effectively Become “10 Years”?

Why has the threshold increased from five to ten years?

One key factor is the Japanese government’s evolving policy on the acceptance of foreign workers, particularly in sectors prioritised by the government to address labour shortages.

The focus is no longer solely on the fact that someone has lived in Japan for a certain period, but on whether they can be regarded as a stable member of society who understands and follows social norms and can live independently within the community.

A period of ten years is now considered a meaningful benchmark for making this assessment.

Alignment with Permanent Residence Requirements

Another major reason for this change is consistency with permanent residence (PR) requirements.

Under the previous framework

Permanent Residence	Generally required 10 years of residence (with some exceptions)
Naturalisation	Generally possible after 5 years (with some exceptions)

This created a “reverse situation” in which becoming a Japanese national was, in some cases, easier than remaining a foreign national with permanent residence status.

The recent changes aim to correct this imbalance by requiring equal or greater levels of stability and achievement for naturalisation, given the significance of acquiring Japanese nationality.

Important: The Law Itself Has Not Changed

One crucial point is that the Nationality Act itself has not been amended. Article 5 still clearly states the requirement of “five years’ residence in Japan.”

However, the Minister of Justice, who ultimately decides whether to grant naturalisation, has broad discretionary authority.

In other words, even if the statutory minimum requirement is met, the government (the Ministry of Justice) will make a comprehensive judgement based on current social conditions in Japan.

It is therefore not a strict rule of “10 years” in every case, but rather “10 years as a general guideline.”

There remains scope for approval in less than ten years where special circumstances exist, such as exceptional contributions to Japan and a stable family life through marriage to a Japanese national.

Applications Submitted Before 31 March May Also Be Affected

Another important point is that even applications submitted before 31 March 2026 may be affected.

According to the Ministry of Justice, if approval has not yet been granted by that date, the application may be reviewed under the new, stricter standards.

Applicants may be asked to submit additional documents and provide more detailed explanations regarding their background.

In such cases, the key to approval is to remain calm and submit accurate and well-prepared information.

Key Focus of Screening: Expanded Review of Tax and Social Insurance Compliance

Even more important than the length of residence is compliance with public obligations. The period subject to review has been significantly expanded:

Category	Before	From 1 April
Taxes (resident tax, income tax, etc.)	Most recent 1 year	Approximately past 5 years
Social insurance (pension, health insurance)	Most recent 1 year	Approximately past 2 years

Previously, unpaid pension contributions could often be settled before application without major issues.

Going forward, however, a distinction is likely to be made between payments made on time, and payments made after the deadline.

Last-minute payments immediately before application will no longer be sufficient.

Periods of non-enrolment during job changes, or even minor delays in payment, will be carefully scrutinised.

Four Key Preparations for Future Naturalisation Applications

1. Take a Long-Term Perspective: Plan for a 10-Year Stay

With the effective shift to a 10-year standard, simply residing in Japan is no longer enough. Stability of life is now a central focus.

• Be cautious about changing jobs immediately before applying, as this may raise concerns about income stability

• Aim to maintain stable employment and an annual income of around JPY 3 million or more (household income may be considered)

• Carefully manage time spent outside Japan (Absences of over 90 days at a time, or over 100 days per year, may reset your residency period.)

  
  

2. Perfect Compliance: Pay Taxes and Insurance On Time

This is now one of the strictest areas of review. Not only whether you have paid, but whether you paid on time is expected to be critical.

• Even a one-day delay may negatively affect your application

• Particular care is needed during transitions to freelance work or between jobs

• Consider setting up automatic payments or payroll deductions

• Ensure that family members living with you are also fully compliant, as their status may affect your application

  
  

3. Review Your Legal History

“Good conduct” is an essential requirement. Issues that may seem minor can be taken seriously in screening.

• Multiple minor traffic violations (e.g. more than three in two years) may lead to refusal

• Serious offences such as drink driving carry a very high risk of refusal

• Check that there are no inconsistencies with your immigration history, including excessive part-time work during student status and any discrepancies in previously declared activities

4. Continue Improving Your Japanese Language Skills

Naturalisation is the process of becoming Japanese, so integration into society is essential.

• A general benchmark is literacy equivalent to a third-year primary school student

• However, interviews require the ability to clearly express your thoughts in Japanese

• Participation in local community activities may positively demonstrate integration

• Prepare for the final interview by being able to explain your motivation and life in Japan honestly and logically in Japanese

  
  

Impact on Foreign Residents in Shiga and Kyoto and How an Administrative Lawyer Can Help

Shiga and Kyoto are home to many foreign residents with diverse visa statuses, including those working in manufacturing, tourism, and research.

For those planning to apply for naturalisation from a work visa, the effective extension to “10 years” can have a significant impact.

Plans based on applying “in one more year” may now need to be postponed by several years, requiring a reassessment of life plans.

With these stricter standards, applying without professional guidance carries increased risk.

If you have any concerns, such as whether you may qualify for an exception (e.g. simplified naturalisation) and how to address past non-payment issues, it is advisable to consult a qualified Administrative Lawyer to properly assess your situation.

A steady and well-prepared approach is the most reliable path towards the significant goal of acquiring Japanese nationality.