Japanese citizenship · 国籍 · children

Japanese nationality for children: by birth, by acknowledgment and with the parents

A child of a Japanese national is Japanese from birth — but a child born abroad must have the nationality reserved within 3 months. A child acknowledged by a Japanese parent gets it by notification; children of foreign parents naturalize together with them. Every case under the Nationality Act, and the rules for two nationalities.

Reservation after a birth abroadWithin 3 months

Acknowledged childNotification, under 18

Residence for a child of a JapaneseNone required

Choose one nationalityBy age 20

In short

Which case is yours

Japan follows the right of blood (jus sanguinis): a Japanese parent passes on the nationality, the place of birth does not.

Situation How the child becomes Japanese Article
Father or mother is Japanese at the time of birth Automatically, from birth 2
The same, but born abroad with another nationality at birth Reserve Japanese nationality within 3 months (国籍留保) 12
Reservation missed, child under 18 and living in Japan Notification to the Minister of Justice 17
Acknowledged by a Japanese parent after birth, under 18 Notification to the Minister of Justice 3
Child of a Japanese national, living in Japan, but not Japanese Naturalization without residence, age or income conditions 8(1)
Foreign parents naturalize Naturalization together with the parents in practice
Born in Japan to foreign parents Naturalization after 3 years in Japan 6(2)
Adopted by a Japanese national while a minor Naturalization after 1 year in Japan 8(2)

By birth

A child of a Japanese national is Japanese from birth

Acknowledgment (認知)

If the parents were not married

  • the child is under 18;
  • the acknowledging parent was Japanese when the child was born and is Japanese now (or was Japanese at death);
  • the acknowledgment is true — a false acknowledgment gives no nationality and is a crime.

Together with the parents

Naturalizing as a family

When foreign parents naturalize, their minor children usually apply together with them.

How it works

  • In practice the children are not judged on their own residence period, age or income — even if they have lived in Japan for less than 10 or 5 years.
  • What matters is that the parents meet the conditions.
  • After approval the children are entered in the family’s new family register.

What is needed from the child

  • Under 15, the legal representatives apply (Article 18). The Tokyo Legal Affairs Bureau asks both parents to come.
  • Under 15, no statement of motivation (帰化の動機書) and no oath (宣誓書); in practice no interview.
  • From 15, the child applies in person and is interviewed.
  • School certificates; in practice the bureau also looks at the school child’s Japanese.

Born in Japan

A child of foreign parents born in Japan

Dual nationality

Until what age a child can have two nationalities

  • if the second nationality came before 18 — choose by age 20;
  • if it came after 18 — within 2 years;
  • to choose Japan, give up the other nationality, or file a declaration of choice of Japanese nationality (選択の宣言) at the city office or a Japanese embassy — after that you must try to give up the other nationality (Article 16);
  • if you do not choose in time, the Minister of Justice may send a written reminder; if you still do not choose within 1 month of it, Japanese nationality is lost (Article 15).

FAQ

Questions about children

Only if the father or mother is a Japanese national, or if the parents are unknown or stateless. Being born in Japan is not enough. A child of foreign parents born in Japan can naturalize after 3 years of living in Japan — from age 18 alone, or earlier together with the parents.
If the child also got another nationality at birth, file the birth report with a reservation of Japanese nationality (国籍留保) at a Japanese embassy or consulate within 3 months of the birth. Otherwise the child loses Japanese nationality back to the date of birth.
For a time. A child who has both from birth must choose one by age 20; if the second nationality came after 18, within 2 years.
In practice, no. Minor children who apply with their parents are not judged on their own residence period or income — what matters is that the parents meet the conditions.
Under 15, the legal representatives (usually the parents) apply in person; the Tokyo Legal Affairs Bureau asks both parents to come. From 15, the child applies in person and is interviewed.
No, if the child is under 18. A notification to the Minister of Justice (Article 3), filed at the Legal Affairs Bureau or a Japanese embassy, is enough. Nationality starts on the day of the notification.
A child under 18 who lost Japanese nationality this way can get it back by notification to the Minister of Justice while living in Japan (Article 17).

Sources

Where this information comes from

Facts were checked on 7 October 2026 against the Nationality Act (国籍法) and the Family Register Act (戸籍法) on e-Gov, the website of the Ministry of Justice and the Legal Affairs Bureaus (法務局). The Ministry publishes no figures for some points — how long a trip abroad breaks your residence, what income is enough, how long the review takes. There we rely on what Japanese administrative scriveners (行政書士) consistently report and say “in practice”.

This page is general information, not legal advice. The Minister of Justice decides each application, and the Legal Affairs Bureau may ask for more documents. Rules for your current nationality come from your own country’s law.

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