Japan does not allow dual citizenship for adults. Naturalization means giving up your previous nationality — a significant decision. Here’s everything you need to know before applying.


Basic Requirements

To be eligible for naturalization, you generally need to meet all of the following:

RequirementDetails
Continuous residence5+ years living in Japan (uninterrupted)
Age20+ years old (Japan’s age of majority)
Good conductNo criminal record in Japan or abroad
Financial stabilityAble to support yourself and dependents
Willingness to renounceGive up your current nationality
Japanese languageN2 equivalent or above recommended (not officially required but expected)

Special Cases with Shorter Residency Requirements

Some applicants can qualify with fewer years of residence:

  • Spouse of Japanese national: 3 years of marriage AND residing in Japan for 1+ year
  • Child of Japanese national: 1 year of residence (or 0 if born in Japan and always lived there)
  • Former Japanese national: Special rules apply

The Application Process

Step 1: Gather Documents

Required documents include (but are not limited to):

  • Passport (current and previous)
  • Residence Card
  • Family Register (戸籍謄本) or equivalent from home country
  • Tax payment records (3–5 years)
  • Employment certificate or business registration
  • Bank statements
  • Criminal background check from home country
  • Autobiographical statement (自己紹介書)
  • Reason for naturalization (動機書)

The full document list runs to 30+ items and varies by nationality.

Visit your nearest 法務局 (Legal Affairs Bureau / Ministry of Justice office). Staff will review your documents informally and tell you what you still need before formal submission. This step is mandatory and very helpful.

Step 3: Formal Submission

Once your documents are complete, submit formally at the Legal Affairs Bureau. A caseworker is assigned.

Step 4: Investigation Period

The Ministry of Justice investigates your background, finances, language ability, and integration. This includes:

  • A Japanese language test (reading, writing, and sometimes interview)
  • A home visit (not guaranteed but possible)
  • Tax and financial checks

Step 5: Decision

Processing time: 1–2 years on average after formal submission. Some cases take longer.

If approved, you receive an official notification and must renounce your previous citizenship within a set period.


Giving Up Your Current Citizenship

Japan does not recognize dual citizenship for adult naturalized citizens. Upon naturalization, you must:

  1. Renounce your previous citizenship
  2. Notify the relevant authority in your home country

Note: What Japan requires of you is to renounce. Whether your home country recognizes this or forces a separate formal process varies. US citizens must formally renounce at a US embassy — this is a separate process from Japanese naturalization.

Some countries (UK, Australia, etc.) may allow you to retain their citizenship technically even after Japanese naturalization — Japan won’t track this, but it’s legally ambiguous.


What You Gain with Japanese Citizenship

  • Japanese passport — one of the world’s most powerful (193 countries visa-free)
  • Right to vote in Japanese elections
  • No more visa renewals, no departure anxiety
  • Right to work any job without restriction
  • Full social equality (some jobs, including government positions, require citizenship)

Is Naturalization Worth It?

Consider carefully if:

  • Your home country passport is already strong (US, UK, EU, Australia) — the gain in travel freedom is minimal
  • You have property, inheritance, or business interests that depend on your home citizenship
  • You plan to eventually return to your home country

Naturalization makes most sense if:

  • You’re planning to stay in Japan permanently
  • Your home country passport has significant visa restrictions
  • You have children who will grow up in Japan

Permanent Residency vs. Citizenship

Permanent residency is often a better intermediate option — you keep your passport and get most of the same daily-life benefits. Citizenship is the full commitment.