Japanese citizenship by descent: who qualifies, the law, and what it takes

Q: Can you claim Japanese citizenship through a parent?

Possible. A child of a Japanese parent is Japanese at birth. If you also picked up another nationality at birth — most often by being born in a country that grants it by birthplace — that only holds if a reservation of Japanese nationality was filed within three months of your birth; missing that window loses it permanently, with no way to revive it later. Either way, Japan will expect a choice of one nationality by 22. If the parent is your mother and you were born before 1985: unlikely.

Q: Can you claim Japanese citizenship through a grandparent?

Unlikely. Japanese nationality does not reach a grandchild or great-grandchild directly; the claim runs through whether your parent was, and remained, a Japanese national at your birth. If not, the closest official route is the Long-Term Resident visa for second- and third-generation people of Japanese descent, which gives open work rights but not citizenship.

Q: Can you claim Japanese citizenship through a great-grandparent?

Unlikely. Japanese nationality does not reach a grandchild or great-grandchild directly; the claim runs through whether your parent was, and remained, a Japanese national at your birth. If not, the closest official route is the Long-Term Resident visa for second- and third-generation people of Japanese descent, which gives open work rights but not citizenship.

Through a parentCitizenship at birth, subject to reservation (Art. 2(i), Art. 12)Through a grandparentTwo or more generations Through a great-grandparentTwo or more generations

Routes: Citizenship at birth through a parent (Art. 2(i)) · Reservation of Japanese nationality for a child born with dual nationality (Art. 12)
Dual citizenship: Not kept: the law expects you to give up your other citizenship

The stamps assume no one in the line became a citizen of another country before the next person in the line was born. What changes each answer is below.

On this page

01Who qualifies
02Dates that matter
03Mothers’ lines
04Keeping your citizenship
05The routes and the law
06The documents
07What it takes
08Where the records live
09Law changes
10Other doors
11Sources

01Who qualifies

Who qualifies, generation by generation

POSSIBLE

Can you claim Japanese citizenship through a parent?

Citizenship at birth, subject to reservation (Art. 2(i), Art. 12)

A child of a Japanese parent is Japanese at birth. If you also picked up another nationality at birth — most often by being born in a country that grants it by birthplace — that only holds if a reservation of Japanese nationality was filed within three months of your birth; missing that window loses it permanently, with no way to revive it later. Either way, Japan will expect a choice of one nationality by 22.

What would settle itWhether you acquired a foreign nationality at birth, and if so, whether the reservation of Japanese nationality was filed within three months; that single fact decides this case.

A child is a Japanese national at birth if the father or the mother is a Japanese national at the time of birth. Nationality Act (Act No. 147 of 1950, as amended), Art. 2(i)
A child born abroad who acquires a foreign nationality at birth loses Japanese nationality retroactively from birth unless a notification of reservation of Japanese nationality is filed with the birth registration within three months, at a Japanese embassy, consulate or municipal office. Nationality Act (Act No. 147 of 1950, as amended), Art. 12
The three-month deadline is strict; a registration filed even one day late cannot be accepted, and Japanese nationality is then treated as never having existed from birth. Ministry of Justice: Nationality Q&A — notification of reservation of Japanese nationality
Once recognised, you must choose one nationality before turning 22, or within two years of acquiring the second nationality if that came at or after 20. Nationality Act (Act No. 147 of 1950, as amended), Art. 14

What changes the answer

UNLIKELY
If the parent is your mother and you were born before 1985Citizenship at birth (pre-1985 law)
Before the law was made gender-neutral on 1 January 1985, a child of a Japanese mother and foreign father generally did not acquire Japanese nationality at birth unless the father was stateless or unknown.

UNLIKELY

Can you claim Japanese citizenship through a grandparent?

Two or more generations

Japanese nationality does not reach a grandchild or great-grandchild directly; the claim runs through whether your parent was, and remained, a Japanese national at your birth. If not, the closest official route is the Long-Term Resident visa for second- and third-generation people of Japanese descent, which gives open work rights but not citizenship.

What would settle itWhether your parent held Japanese nationality at your own birth, which would put you on the parent route instead.

A child is a Japanese national at birth only if the father or the mother is a Japanese national at the time of birth; the Act does not extend this to grandparents. Nationality Act (Act No. 147 of 1950, as amended), Art. 2(i)
Second- and third-generation descendants of a Japanese national can be granted Long-Term Resident status, proved with the Japanese ancestor's family register (koseki), giving unrestricted work rights without residence sponsorship. Immigration Services Agency: guidance for second- and third-generation persons of Japanese descent (Long-Term Resident status)

UNLIKELY

Can you claim Japanese citizenship through a great-grandparent?

Two or more generations

What would settle itWhether your parent held Japanese nationality at your own birth, which would put you on the parent route instead.

A child is a Japanese national at birth only if the father or the mother is a Japanese national at the time of birth; the Act does not extend this to grandparents. Nationality Act (Act No. 147 of 1950, as amended), Art. 2(i)
Second- and third-generation descendants of a Japanese national can be granted Long-Term Resident status, proved with the Japanese ancestor's family register (koseki), giving unrestricted work rights without residence sponsorship. Immigration Services Agency: guidance for second- and third-generation persons of Japanese descent (Long-Term Resident status)

02Dates that matter

The dates that matter

1985
1 January 1985
The 1984 amendment, in force from 1 January 1985, first allowed a mother's Japanese nationality to pass to her child on the same terms as a father's; it was not retroactive to older births. Nationality Act (Act No. 147 of 1950, as amended)

03Mothers’ lines

How mothers’ lines were treated

In Japan’s rule, the answer changes when the line runs through a woman:

UNLIKELY
If the parent is your mother and you were born before 1985Citizenship at birth (pre-1985 law)
Before the law was made gender-neutral on 1 January 1985, a child of a Japanese mother and foreign father generally did not acquire Japanese nationality at birth unless the father was stateless or unknown.

In the law’s words

The 1984 amendment, in force from 1 January 1985, first allowed a mother's Japanese nationality to pass to her child on the same terms as a father's; it was not retroactive to older births. Nationality Act (Act No. 147 of 1950, as amended)
A child is a Japanese national at birth if the father or the mother is a Japanese national at the time of birth. Nationality Act (Act No. 147 of 1950, as amended), Art. 2(i)
A child is a Japanese national at birth only if the father or the mother is a Japanese national at the time of birth; the Act does not extend this to grandparents. Nationality Act (Act No. 147 of 1950, as amended), Art. 2(i)

04Keeping your citizenship

Dual citizenship with your home country

Dual citizenship is not guaranteed.

On every open route, the rule expects a citizen of the United States, Canada, the United Kingdom, Australia, New Zealand, Brazil, Argentina or South Africa to give up their other citizenship, or to get permission to keep it.

A Japanese national who also holds a foreign nationality must declare a choice of nationality before turning 22 (or within two years of acquiring the second nationality, if that came at or after 20), and choosing Japan requires an effort to give up the other nationality. Ministry of Justice: Choice of Nationality

05The routes

Every route, and the law behind it

Citizenship at birth, subject to reservation (Art. 2(i), Art. 12)

Open through a parent

POSSIBLE
Through a parent

The law

A child is a Japanese national at birth if the father or the mother is a Japanese national at the time of birth. Nationality Act (Act No. 147 of 1950, as amended), Art. 2(i)
A child born abroad who acquires a foreign nationality at birth loses Japanese nationality retroactively from birth unless a notification of reservation of Japanese nationality is filed with the birth registration within three months, at a Japanese embassy, consulate or municipal office. Nationality Act (Act No. 147 of 1950, as amended), Art. 12
The three-month deadline is strict; a registration filed even one day late cannot be accepted, and Japanese nationality is then treated as never having existed from birth. Ministry of Justice: Nationality Q&A — notification of reservation of Japanese nationality
Once recognised, you must choose one nationality before turning 22, or within two years of acquiring the second nationality if that came at or after 20. Nationality Act (Act No. 147 of 1950, as amended), Art. 14

What would settle an unsure case

Whether you acquired a foreign nationality at birth, and if so, whether the reservation of Japanese nationality was filed within three months; that single fact decides this case.

Citizenship at birth (pre-1985 law)

Closed: no open answer on this route

UNLIKELY
Through a parent, if the parent is your mother and you were born before 1985
Before the law was made gender-neutral on 1 January 1985, a child of a Japanese mother and foreign father generally did not acquire Japanese nationality at birth unless the father was stateless or unknown.

The law

The 1984 amendment, in force from 1 January 1985, first allowed a mother's Japanese nationality to pass to her child on the same terms as a father's; it was not retroactive to older births. Nationality Act (Act No. 147 of 1950, as amended)

What would settle an unsure case

Whether your mother's Japanese nationality was ever recognised for you through a special provision, or whether your father was stateless at your birth.

Two or more generations

Closed: no open answer on this route

UNLIKELY
Through a grandparent
Japanese nationality does not reach a grandchild or great-grandchild directly; the claim runs through whether your parent was, and remained, a Japanese national at your birth. If not, the closest official route is the Long-Term Resident visa for second- and third-generation people of Japanese descent, which gives open work rights but not citizenship.

The law

A child is a Japanese national at birth only if the father or the mother is a Japanese national at the time of birth; the Act does not extend this to grandparents. Nationality Act (Act No. 147 of 1950, as amended), Art. 2(i)
Second- and third-generation descendants of a Japanese national can be granted Long-Term Resident status, proved with the Japanese ancestor's family register (koseki), giving unrestricted work rights without residence sponsorship. Immigration Services Agency: guidance for second- and third-generation persons of Japanese descent (Long-Term Resident status)

What would settle an unsure case

Whether your parent held Japanese nationality at your own birth, which would put you on the parent route instead.

06The documents

The documents, as the rule lists them

Citizenship at birth, subject to reservation (Art. 2(i), Art. 12)

Through a parent

Your parent's koseki (family register) entry
Your birth certificate
Proof the reservation of nationality was filed within three months of your birth, or that you were not born with another nationality

Most countries also want proof that no one in the line became a citizen elsewhere before the next birth: the naturalization record with its date, or a letter that none exists.

07What it takes

What it takes: time, cost, the hard part, who decides

Citizenship at birth, subject to reservation (Art. 2(i), Art. 12)

Time: A few weeks for the koseki (family register) entry once the nationality-reservation notice is accepted, then 2–4 weeks for a first passport.
Cost: About $100–250: certified koseki copies, translations, and the passport fee. The reservation notice itself is free.
The hard part: Filing the nationality-reservation notice within three months of the birth. Miss the deadline and Japanese nationality is lost retroactively, with no way to revive it later.
Who decides: The Japanese embassy or consulate for your address, for the birth report and nationality reservation within three months; then a passport application at the same post.
The first record: Your parent’s koseki (family register) entry showing them as a Japanese national, from The Japanese municipal office holding the family’s koseki, or the nearest Japanese embassy or consulate. Request a certified koseki tōhon (full transcript) by mail or in person, giving the registered address (honseki) and the parent’s full name; embassies can also help identify the honseki if the family has lost track of it. moj.go.jp

How it’s filed

Where: The Japanese embassy or consulate for your address, within three months of the birth; a municipal office if filing from Japan.
How: In person; you appear in person
Form: Birth report (shussho todoke) with the nationality-reservation box completed, filed at a Japanese embassy or consulate or a municipal office in Japan
Fee: No fee
Decision: 2–13 weeks

What goes in the file (5)

The birth report (shussho todoke), with the nationality-reservation column completed and signed
Your U.S. birth certificate, translated into Japanese
Your parent's koseki tōhon (family register transcript)
Your parents' marriage certificate, translated, if applicable
Passport-style photos and identification, as the post's checklist asks

What goes wrong (3)

The nationality-reservation notice must reach the embassy, consulate or municipal office within three months of the birth; a report accepted even one day late cannot restore Japanese nationality once it has lapsed.
There is no fee for the birth report or the reservation notice itself; the koseki entry and later passport carry their own small fees.
Once the koseki entry is made, a first Japanese passport is a separate, later application at the same post.

Checked 25 September 2026 · source ↗

Estimates are honest ranges from official fee tables and what families report; where a fee or time could not be confirmed, it says so.

08Where the records live

Where each record lives, and how to ask for it

birth
The Japanese municipal office holding the family's koseki (family register), reached through a Japanese embassy or consulate for a birth abroad
Give the registered address (honseki) and the parent's full name; the embassy or consulate can help trace the honseki if the family has lost track of it.
Ask
Through an agent, in Japanese · request page ↗
Takes
2–9 weeks
Good to know (2)
- The koseki tōhon (full transcript) is the document everything else relies on; request several certified copies at once since almost every later step wants its own.
- Unverified: exact turnaround and fee for a koseki request made from abroad through a consulate rather than in person in Japan.
Checked 25 September 2026 · source ↗

Translations

Into: Japanese
Who may translate: Any certified translator
About: $20–$45 a page

U.S. birth and marriage certificates filed with a Japanese embassy, consulate or municipal office need a Japanese translation; no sworn or embassy-approved translator is required. Unverified: whether a specific consulate insists on its own translation template.

Checked 25 September 2026 · source ↗

The passport

Where: A Japanese embassy or consulate, once the koseki entry recording the birth is in hand.
Fee: Not confirmed
Time: 2–4 weeks

Passport fee shown as a placeholder; consulates price a 5- and 10-year passport differently and by page count.

Checked 25 September 2026 · source ↗

09Law changes

Recent and pending changes

The legislative watch has no pending bill or recent ruling recorded for Japan.

The watch re-reads the official pages behind this guide every day. When one changes, a person re-checks the rule before anything here moves.

10Other doors

If descent doesn’t reach you

2 residence programs lead to Japan without an ancestor, each with its own law and road to citizenship.

11Sources

Every source on this page

4 laws and official pages behind the answers, then the offices and pages behind the records and filing. Records and filing checked 25 September 2026.

LawNationality Act (Act No. 147 of 1950, as amended) · Art. 2(i); Art. 12; Art. 14
LawMinistry of Justice: Nationality Q&A — notification of reservation of Japanese nationality · checked 25 September 2026
LawImmigration Services Agency: guidance for second- and third-generation persons of Japanese descent (Long-Term Resident status)
LawMinistry of Justice: Choice of Nationality · checked 25 September 2026
RecordsTranslations into Japanese · checked 25 September 2026

Not legal advice. Postern’s rulebook is written from the statutes and tested against documented cases; where the law is unsettled, the answer says “possible” or “unsure” rather than guess.

Who qualifies, generation by generation

Can you claim Japanese citizenship through a parent?

What changes the answer

Can you claim Japanese citizenship through a grandparent?

Can you claim Japanese citizenship through a great-grandparent?

The dates that matter

How mothers’ lines were treated

In the law’s words

Dual citizenship with your home country

Every route, and the law behind it

The law

What would settle an unsure case

The law

What would settle an unsure case

The law

What would settle an unsure case

The documents, as the rule lists them

Citizenship at birth, subject to reservation (Art. 2(i), Art. 12)

What it takes: time, cost, the hard part, who decides

Citizenship at birth, subject to reservation (Art. 2(i), Art. 12)

How it’s filed

Where each record lives, and how to ask for it

Translations

The passport

Recent and pending changes

If descent doesn’t reach you

Every source on this page

Check your family for Japan.