How to Choose Your Japanese Name for Naturalization｜Rules for Kanji, Nicknames, and Name Readings

How to Choose Your Japanese Name for Naturalization｜Rules for Nicknames, Kanji, and Readings in Official Registration

When applying for naturalization in Japan, one of the first questions people face is:
“How should I decide my Japanese name?”

Can you continue using the nickname you’ve used for years?
Are there restrictions on kanji?
Can you freely decide how your name is read?

This article explains how names are officially registered in the Japanese family register (koseki) after naturalization.
Based on actual legal practice and guidance from the Ministry of Justice, I’ll summarize the key points to help you choose a name you’ll never regret.

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Why You Need a Japanese Name When Applying for Naturalization

When you obtain Japanese nationality, a Japanese-style name must be registered in the family register.
In other words, your passport name or foreign spelling cannot be used as-is—you will need to adopt a name written in Japanese characters.

The authorities expect:

• A name that fits naturally into Japanese society
• A name that can be recognized and used in everyday life

If you have lived in Japan for many years, you may already have a tsūshō-mei (commonly used Japanese nickname).
In many cases, such a name can be officially adopted—but only if it has been consistently used in social life.

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Can I Use My Nickname? How Authorities Handle Commonly Used Names

If you have used a nickname for a long time in Japan, it can generally be accepted as your legal name after naturalization.
However, you will need to prove that you have been using it socially.

Typical documents that demonstrate usage include:

• A residence record (住民票) showing both your legal and common name
• Payslips, company rosters, or ID cards that list the name
• Utility bills, bank accounts, or insurance policies under that name

Practical tip: When submitting your application, it’s best to show consistent use across two or three types of documents.
That makes it easier for the examiner to verify your nickname’s legitimacy.

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Kanji Rules｜Which Characters You Can (and Cannot) Use

Because your new name will appear in the family register, the characters you can use are legally restricted under the Family Registration Act.
You can only use:

• Common-use kanji (常用漢字)
• Approved name-use kanji (人名用漢字)
• Hiragana or katakana

Old or uncommon characters are generally not allowed.
For example, characters such as “髙 (tall with ladder form)” or “﨑 (old form of saki)” may need to be simplified.
Alphabet letters, symbols, and punctuation marks (・ / － etc.) are also not accepted.

Example:
“Maria Smith” → can be rendered as 「マリア スミス」 (katakana) or 「真里亜 住美寿」 (kanji), depending on preference.

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Readings Are Free｜How Pronunciation and Unusual Readings Are Treated

One surprising fact is that the family register has no field for pronunciation.
This means you can technically choose any reading for your name.

However, in practice, the Legal Affairs Bureau may ask you to adjust names that are too unconventional or unnatural in Japanese.

Examples:

• 「光」 read as Hikaru → OK
• 「光」 read as Light → likely to be rejected

Tip: Even though readings are not restricted by law, names that are easy to pronounce and socially acceptable are preferred.

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From Application to Registration｜When Your Name Becomes Official

The name you write on your naturalization application will ultimately be registered in your family register.
Here’s the process:

1. You fill in your desired name on the naturalization application.
2. After approval, the Legal Affairs Bureau instructs your local government office to create your new family register.
3. Once the register is completed, your Japanese name becomes official.

After registration, name changes are extremely difficult.
They require permission from a family court, and will only be approved for unavoidable reasons.
That’s why it’s essential to choose carefully before applying.

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FAQ: Common Questions About Japanese Names After Naturalization

Q1. Can I still use my old (foreign) name after naturalization?

Yes, socially you can continue using it. However, your official name on the family register will be your Japanese name.

Q2. Can I keep my English or native name?

You can, but only in katakana or hiragana form. For example, “Maria” → 「マリア」.

Q3. What if my new surname is very common in Japan?

No problem. The family register allows duplicate names.

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Tips from an Administrative Scrivener: Choosing a Name You’ll Never Regret

• Think ahead 3–10 years — choose a name that’s easy to write, read, and pronounce.
• Decide whether to unify your family’s names or select an individual one.
• Consider how your new name will appear on bank accounts, seals, and passports.

At Ishinagi Administrative Scrivener Office, we can check candidate names for legal compliance and help you confirm what’s acceptable under the Family Registration Act.
We provide full support, from name planning to document preparation.

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Conclusion｜Your Naturalization Name Is Part of Your Life Plan

Once registered, your name is almost impossible to change.
Understanding the rules for nicknames, kanji, and readings will help you choose a name that feels right and works well in society.

At Ishinagi Administrative Scrivener Office, we provide complete assistance for name selection and naturalization applications in Japan.

Ishinagi Administrative Scrivener Office

If you want to obtain Japanese nationality quickly and securely, or if you feel uncertain about preparing the required documents, please feel free to consult our office in Yodogawa-ku, Osaka.
We handle requests from all over Japan and provide the most suitable support based on our experience with immigration procedures and applications to the Legal Affairs Bureau.

If you wish to proceed with your naturalization application smoothly and with confidence, please don’t hesitate to contact us.

▶ See our fee schedule here

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