Dual Nationality for Japanese Children Born Abroad: Article 14

Regulatory & Legal Advisory: Educational & Informational Content Only

The procedures, legal frameworks, tax laws, and visa requirements described in this guide reflect official guidelines and regulatory synthesis current as of publication. Immigration policies, tax treaties, and municipal requirements change frequently. This content is for educational and planning purposes only and cannot substitute for formal legal, tax, or immigration counsel. Readers must verify current requirements directly with relevant municipal city halls, the National Tax Agency (NTA), the Japan Pension Service, official embassies, or certified professional advisors (licensed immigration lawyers, certified tax accountants / Zeirishi).

A child born abroad to a Japanese parent can hold Japanese and a foreign nationality from birth, but Japanese law attaches two deadlines to that status.¹ The first is a nationality reservation (Kokuseki Ryuho 国籍留保) filed with the birth notification within 3 months; the second is a choice of nationality by age 20, or within 2 years if dual nationality arises after reaching 18.¹² This guide explains both deadlines, what happens if either is missed, and how the selection declaration and passports work.

Overview & Eligibility Framework

Japan’s Approach: One Nationality, With Deadlines Rather Than a Ban at Birth

Japanese nationality passes by descent through either parent. Under Article 2(i) of the Nationality Act (Kokuseki Ho 国籍法), a child is Japanese if the father or the mother is a Japanese national at the time of birth.¹ A second nationality can arise at the same moment from the other parent or from the country of birth.

Japan does not prevent dual nationality from arising at birth. Instead it attaches a reservation requirement to births abroad (Article 12) and a duty to choose one nationality (Article 14), and loss for failing to choose requires a further step by the Minister of Justice (Article 15).¹ The Ministry of Justice (MOJ) gives two reasons for requiring a choice: possible international friction from conflicting rights of diplomatic protection, and possible confusion in civil status because one person is registered differently in each country.³

The government restated its position in June 2026. On 9 June 2026 the Vice-Minister of Justice told a House of Councillors committee that the current Nationality Act basically does not permit dual nationality and that wider acceptance would require careful consideration (as of October 2026).⁴

Who This Guide Applies To

This guide is for families whose child is, or may be, both Japanese and something else. That includes children born abroad who acquire a foreign nationality at birth, children born in Japan to a Japanese and a foreign parent, and children who acquire one later through recognition, adoption or marriage.⁵³ If it is hard to tell whether your child holds two nationalities, MOJ advises asking the nearest Legal Affairs Bureau (Homukyoku 法務局).³

Related topics have their own guides. Adult naturalisation abroad is covered in the guide to departure rules for Japanese citizens and foreign residents, and consular registration and schooling in the guides on consular services, schooling abroad and Japanese supplementary schools.

How Dual Nationality Arises: Jus Soli, Jus Sanguinis and Later Events

The Five Typical Cases Listed by the Ministry of Justice

MOJ describes five common patterns, each tied to the nationality law of the other country.⁵³ They are examples, and MOJ cautions that foreign laws may have changed since it wrote them.

Pattern	MOJ example	How the second nationality arises
Japanese mother, father from a country that passes nationality through the father	Japanese mother, Kuwaiti father	Descent through the father
Japanese parent, other parent from a country that passes nationality through either parent	One parent Japanese, the other Korean	Descent through the foreign parent
Japanese parent or parents, birth in a country that grants nationality by birthplace	Born in the United States, Canada, Brazil or Peru	Birth on the territory (jus soli)
Japanese national who later gains a foreign nationality by a civil-status act	Child of a Japanese mother recognised by a Canadian father	Recognition, adoption or marriage
Person who acquired Japanese nationality by notification	Former foreign national keeps the old nationality	The earlier nationality continues

Only the Foreign Country Can Say Whether Your Child Holds Its Nationality

Deciding who holds a nationality is the exclusive prerogative of each state. MOJ therefore says that whether a person holds a foreign nationality must be confirmed with that foreign country’s authorities.⁵³ In December 2021 MOJ’s Civil Affairs Bureau Director-General told the Diet that the government cannot accurately grasp how many Japanese nationals hold another nationality.⁶

The United States illustrates birthplace-based citizenship. Under section 1401(a) of Title 8 of the US Code, a person born in the United States and subject to its jurisdiction is a citizen at birth, and on 30 June 2026 the Supreme Court held in Trump v. Barbara that this includes children born there to parents unlawfully or temporarily present.⁷⁸

Descent-based rules often carry conditions. Under section 1401(g), a child born abroad to one US-citizen parent and one alien parent is a citizen at birth only if the citizen parent was physically present in the United States for at least 5 years before the birth, at least 2 of them after age 14.⁷ Under section 2(1)(a) of the British Nationality Act 1981, a child born outside the UK is British if a parent is a British citizen “otherwise than by descent”, with service-related exceptions; confirm your child’s position with the foreign authority.⁹

The 3-Month Deadline: Birth Notification With Nationality Reservation (Kokuseki Ryuho)

What Article 12 and Family Register Act Article 104 Require

Article 12 of the Nationality Act is the rule with the hardest edge. A Japanese national born abroad who acquired a foreign nationality by birth loses Japanese nationality retroactively to the time of birth unless the intention to reserve it is expressed under the Family Register Act (Koseki Ho 戸籍法).¹

Family Register Act Article 104 sets the procedure. The reservation must be notified within 3 months of the date of birth, together with the birth notification (Shussei Todoke 出生届), by a person entitled to file the birth.² The fallback filers listed in Article 52(3), such as a cohabitant or the attending doctor or midwife, cannot make it, and the period becomes 14 days from when filing becomes possible only if a natural disaster or other cause not attributable to the filer prevented filing in time.²

In practice the reservation is a statement on the birth notification form. MOJ explains that the father, mother or other legal representative writes “日本国籍を留保する” (Japanese nationality is reserved) on the form within 3 months of birth.³ The Seattle consulate asks the father or mother to sign both the space next to the reservation statement and the filer’s signature space (as of October 2026).¹⁰

Where to File and How the 3 Months Are Counted

You can file at a Japanese embassy or consulate abroad or at a municipal office in Japan. Family Register Act Article 40 allows a Japanese national abroad to file with the Japanese ambassador, minister or consul in that country.²³ In Japan, MOJ lists the municipal office of the child’s birthplace, the registered domicile (Honseki 本籍) or the filer’s location.¹¹

The 3 months are calendar months counted from the day of birth, not 90 days. Family Register Act Article 43(1) counts notification periods from the day the event occurred, so the birth day itself is day one.² The Japanese text of the Seattle consulate’s page gives the example that a child born on 10 April must be registered by 9 July, and its English text states that it cannot accept birth registrations after the 3-month deadline (as of October 2026).¹⁰

Document lists vary by mission, so use your own consulate’s page. Seattle, for example, asks for the form, a certified local birth certificate with a Japanese translation, the Japanese parent’s passport and proof of US immigration status, and asks for the marriage to be registered first if it is not yet in the family register (as of October 2026).¹⁰ Since 1 April 2024 most family register notifications at missions abroad no longer need a copy of the family register, and birth notifications with a reservation never needed one (as of October 2026).¹²

Who Does Not Need a Reservation

Children born in Japan never need a reservation, because Article 12 applies only to those born abroad.¹ A child of two Japanese parents born abroad who acquires no foreign nationality at birth is also outside Article 12.³

These children still need a birth notification within 3 months if born abroad. Family Register Act Article 49(1) sets 14 days for births in Japan and 3 months for births abroad.² Filing late without justifiable reason can lead to a non-penal fine (Karyo 過料) of up to 50,000 yen (Article 137), or up to 100,000 yen if a mayor’s deadline under Article 44 is also missed (Article 138), but for these children lateness does not by itself remove Japanese nationality.²

If the Deadline Was Missed: Re-acquisition Under Article 17(1)

A missed reservation can sometimes be remedied by re-acquisition. Under Article 17(1), a person who lost Japanese nationality under Article 12 may acquire it by notification to the Minister of Justice if they are under 18 and domiciled in Japan.¹ MOJ explains that domicile means the centre of life is in Japan at the time of notification; tourism or family visits do not count.³

The filing is made in person at the Legal Affairs Bureau. The child files, or the legal representative files if the child is under 15 (Article 18).¹³ Nationality is acquired at the time of notification, not retroactively (Article 17(3)), and an acquisition notification must then be filed in the family register within 1 month, or 3 months if the person is abroad on that day (Family Register Act Article 102).¹²

The age limit was under 20 until 1 April 2022, and the 2-year transitional window for those aged 16 or over on that date has closed.¹³ Outside Article 17(1), the route is naturalisation, where Article 8(i) relaxes the residence, age and livelihood conditions for a child of a Japanese national who is domiciled in Japan.¹

Article 14 of the Nationality Act: The Duty to Choose a Nationality

The Deadline Since 1 April 2022: Age 20, or 2 Years After Becoming Dual After Reaching 18

Article 14(1) sets two deadlines depending on when dual nationality arose. If it arose at or before reaching 18, the person must choose one nationality by reaching 20; if it arose after reaching 18, they must choose within 2 years of that time.¹

Many pages still quote the old rule of age 22. Before 1 April 2022 the deadline was age 22, or 2 years for dual nationality arising at 20 or over; the change came with Act No. 59 of 2018, which lowered the age of majority to 18.³

Transitional Rules for People Who Were Already Dual Nationals in 2022

The 2022 change applied only partly to people who were already dual. Under Supplementary Provisions Article 13(2) and (3) of Act No. 59 of 2018, those aged 20 or over on 1 April 2022 kept the old rule and those aged 18 or 19 had 2 years from that date.¹ On our reading, every old-rule and transitional deadline has now passed, and MOJ states that the duty to choose continues after the deadline.¹⁵

People who were dual on 1 January 1985 and did not choose in time are deemed to have made the selection declaration (Supplementary Provisions Article 3 of Act No. 45 of 1984).¹

The Four Ways to Choose

MOJ describes four routes, two that keep Japanese nationality and two that end it.⁵³ For a child under 15, the legal representative files (Article 18).¹

Route	Legal basis	Where	Japanese nationality	Foreign nationality	Follow-up
(a) Renounce the foreign nationality under its law	Nationality Act Article 14(2)	Foreign government or its mission	Kept; dual status ends	Lost under foreign law	Foreign nationality loss notification (Gaikoku Kokuseki Soshitsu Todoke 外国国籍喪失届), Family Register Act Article 106: within 1 month of learning of the loss (3 months if abroad), with proof2
(b) Selection declaration (Kokuseki Sentaku Todoke 国籍選択届)	Article 14(2); Family Register Act Article 104-2	Municipal office or embassy/consulate	Kept; Article 14(1) duty fulfilled	Depends on the foreign country; Article 16(1) effort duty if not lost3	Form states the foreign nationality held2
(c) Renounce Japanese nationality (Kokuseki Ridatsu Todoke 国籍離脱届)	Article 13	Legal Affairs Bureau, or embassy/consulate if domiciled abroad3	Lost on notification	Kept	Proof of the other nationality required; affects only the person, not spouse or children3
(d) Choose the foreign nationality under that country’s law	Article 11(2)	Foreign authority	Lost automatically	Kept	Loss notification (Kokuseki Soshitsu Todoke 国籍喪失届), Family Register Act Article 103: within 1 month of learning of the loss (3 months if abroad)2

Questions about routes (a) and (d) belong to the foreign government or its mission in Japan, and route (d) applies only where the foreign country has a selection system like Japan’s.³

What Happens If No Choice Is Made: The Minister’s Demand (Article 15)

Missing the deadline does not by itself remove Japanese nationality. Under Article 15(1) the Minister of Justice “may” demand a choice in writing, and under Article 15(2) the demand may instead be published in the Official Gazette (Kanpo 官報) if the person’s whereabouts are unknown or written notice is otherwise impossible, in which case it is deemed received the day after publication.¹ A person who does not choose Japanese nationality within 1 month of receiving the demand loses it when that month ends, with a 2-week allowance if a disaster or other cause beyond their control prevented them.¹

Municipal offices must report apparent non-choosers. Family Register Act Article 104-3 requires a mayor who believes a person has not chosen by the deadline to notify the Legal Affairs Bureau.² Re-acquisition after a loss under Article 15 is narrow: Article 17(2) allows it within 1 year of learning of the loss only for a person whose demand was published in the Official Gazette, and only if they meet the Article 5(1)(v) condition (stateless, or would lose the other nationality on acquiring Japanese nationality).¹³

Government statements describe how the demand power has been used. MOJ told a House of Representatives committee in April and May 2009 that no demand had ever been issued, citing the extremely serious effect of loss on the person and relatives, but said a demand would have to be considered if harm from dual nationality seriously damaged national interests; no later statement on the point was found in the Diet record (as of October 2026).¹³ MOJ told the Diet in 2021 that it sent individual reminder notices from 1988 to FY2004 and had relied on publicity since FY2005, while its guidance still says the Minister may issue a demand (as of October 2026).⁶⁵

The Selection Declaration (Sentaku no Sengen): What It Does and Does Not Do

Effect Under Japanese Law

The selection declaration (Sentaku no Sengen 選択の宣言) is a statement that the person chooses Japanese nationality and renounces the foreign nationality. Article 14(2) defines it in those terms, and Family Register Act Article 104-2 makes it a notification on which the foreign nationality held must be stated.¹² MOJ confirms that making the declaration fulfils the Article 14(1) duty to choose.⁵³

Effect Under the Other Country’s Law

Whether the declaration ends the foreign nationality depends on the other country. MOJ says it may not, and in that case Article 16(1) provides that a person who made the declaration “must endeavour to renounce the foreign nationality”.¹³ The text of Article 16(1) itself contains no deadline and no sanction.¹

The foreign side must be checked separately. Under section 1481 of Title 8 of the US Code, for example, a US national loses nationality only by voluntarily performing listed acts with the intention of relinquishing it, so whether a Japanese selection declaration has any effect under US law is a question for US authorities.¹⁴

Foreign Public Office After a Declaration (Article 16(2) to (5))

One further loss rule applies after a declaration. If a declarant who still holds the foreign nationality voluntarily takes up a public post in that country open only to its nationals, and the Minister finds this grossly contrary to the purpose of choosing Japanese nationality, the Minister may declare loss of Japanese nationality after a public hearing.¹ The loss takes effect on the date the declaration is published in the Official Gazette.¹

Choosing for a Young Child: Points for Parents

Parents choose for a child under 15; from 15 the child files personally (Article 18). MOJ describes the choice as one made on the basis of the person’s own will.¹⁵ No official source was found recommending when to choose within the period, so families who are unsure may wish to discuss timing with the Legal Affairs Bureau or the consulate.

The Parent-Application Trap: Loss Under Article 11(1)

Acquired at Birth vs Acquired on Application

How the foreign nationality is acquired matters. A nationality acquired automatically at birth falls under the reservation and choice rules, but Article 11(1) provides that a Japanese national who acquires a foreign nationality “of their own volition” loses Japanese nationality automatically.¹³ Courts have held that an application made by parents on behalf of a child can be the child’s voluntary acquisition.¹⁵¹⁶

Two Tokyo District Court rulings concern Russian nationality acquired through parents’ filings. On 24 June 2016, children of a Japanese father and a Russian mother were held to have lost Japanese nationality after their parents used a Russian simplified citizenship procedure that was not mere birth registration.¹⁵ In a judgment of 18 February 2021, filing the parents’ agreement at the Russian Embassy, knowing it was a nationality procedure, was held to be voluntary acquisition by a legal representative, and Article 11(1) was held constitutional.¹⁶

A further case involving British registration has been reported. News reports state that on 17 October 2024 the Tokyo District Court rejected a constitutional challenge to Article 11(1) in a case concerning a child whose parents completed UK citizen registration for him at age 1; the ruling was not found on the courts’ official database.¹⁷ Before any post-birth foreign “registration”, “naturalisation” or “citizenship application” for a child, it is prudent to confirm with the foreign authority whether the child already holds that nationality by birth, and to consult the Japanese consulate or Legal Affairs Bureau.

Court Rulings on Japan’s Nationality Rules

Article 12 (Reservation) Upheld

Japanese courts have upheld the reservation rule. The Tokyo District Court (23 March 2012) and Tokyo High Court (22 January 2013) found its purposes of preventing nominal Japanese nationality and dual nationality rational, noted the Article 17(1) remedy, and held that Article 12 does not violate Constitution Articles 13 or 14(1).¹⁸

The Supreme Court unanimously dismissed the appeal on 10 March 2015, in a case concerning children born in the Philippines to a Japanese father and a Filipino mother with no reservation, holding that Article 12 does not violate Constitution Article 14(1).¹⁹ Its reasoning relied in part on the Article 17(1) route, then open to those under 20 and now to those under 18.¹⁹¹

Article 11(1) Upheld

Courts have also upheld the voluntary acquisition rule in other cases. The Tokyo District Court held on 21 January 2021 that Article 11(1) does not violate the Constitution, and the Osaka District Court reached the same conclusion on 30 September 2025, adding that officials had no legal duty to publicise the rule.²⁰²¹

Japanese Passports and Border Crossings for Dual-National Children

Getting the First Japanese Passport After the Birth Notification

The Japanese passport normally follows the family register entry. After a birth notification at a mission, the child appears in the family register in about 1 to 2 months according to the Seattle consulate (as of October 2026).¹⁰ MOFA’s 2024 note said new passport applications still required a copy of the family register, so check your mission’s current list before applying (as of October 2026).¹²

Both parents’ consent matters for minors. MOFA’s notice for minors says one parent signs as legal representative and that this is taken as both parents’ consent; if the other parent has filed a written objection, the passport is issued only once both parents’ consent is confirmed (as of October 2026).²²

Entering and Leaving Japan

Japan’s border rules for its own nationals are set by statute. Articles 60 and 61 of the Immigration Control and Refugee Recognition Act (Nyukan Ho 入管法) require a Japanese national leaving or returning to hold a valid passport (on return, a document proving Japanese nationality if unable to hold one) and receive confirmation.²³ No MOFA or Immigration Services Agency web page addressing which passport a dual national presents in Japan was found.

MOFA has described the situation in the Diet in general terms. In 2016 the Consular Affairs Bureau Director-General said that, speaking generally, a dual national using the Japanese passport to leave and enter Japan and the other passport for third countries is a situation that “can be envisaged” (as of October 2026).²⁴ That is a description of what may occur, not guidance, and it does not affect the Article 14 duty to choose.²⁴¹

The Other Country’s Passport Rules

The other country may have its own passport requirement. In the United States, for example, section 1185(b) of Title 8 of the US Code and 22 CFR 53.1(a) make it unlawful for a US citizen, subject to listed exceptions, to enter or depart the United States without a valid US passport.⁷²⁵

Step-by-Step Administrative Procedure & Timeline

The chart below is a simplified sequence; consulate processing times are examples (as of October 2026).¹²⁵³¹⁰

flowchart TD
    A["Before birth: check the other country's nationality rules and your consulate's birth page"] --> B["Within 3 months of birth (birth day counts): birth notification with 'Japanese nationality reserved'"]
    B --> C{"Filed in time?"}
    C -- "Yes" --> D["Family register entry (about 1 to 2 months via a mission)"]
    D --> E["First Japanese passport; foreign documents under that country's rules"]
    C -- "No" --> F["Japanese nationality lost retroactively (Article 12)"]
    F --> G["Under 18 and domiciled in Japan: notification at Legal Affairs Bureau (Article 17(1))"]
    F --> H["Otherwise: naturalisation (Article 8)"]
    E --> I["Age 15: child files personally (Article 18)"]
    I --> J["By age 20 (or within 2 years if dual after reaching 18): choose by one of four routes"]
    J --> K["After the deadline: duty continues; Minister may demand (Article 15)"]

1. Before birth: check the other country’s nationality rules and your consulate’s birth page; register the marriage first if needed.³¹⁰
2. Within 3 months of birth: birth notification with the reservation.²³
3. By the choice deadline: choose, then file any loss notification within 1 month (3 months if abroad).¹²
4. At any time: check Article 11(1) before applying for a foreign nationality for a child.¹⁵¹⁶

Japanese Citizens vs. Foreign Residents: Critical Distinctions

Born Abroad vs Born in Japan

Birthplace decides only the reservation step. The reservation applies only to births abroad, while the Article 14 duty applies to every dual national.¹³

Foreign-National Parents and Foreign-Resident Families

A foreign-national parent may file the birth and the reservation. Family Register Act Article 52(1) lets the father or mother file for a child born in wedlock with no nationality condition, and the Seattle consulate states that a foreign parent may sign the form (as of October 2026).²¹⁰ According to Seattle, a parent who naturalised abroad before the birth has lost Japanese nationality and cannot file the birth registration (as of October 2026).¹⁰

The child’s status and the parents’ status are separate. The child returns to Japan as a national under Article 61, while a foreign parent’s re-entry depends on their own residence status, a point covered in the guide to departure rules for Japanese citizens and foreign residents.²³

Benefits Tied to Japanese Nationality

Holding Japanese nationality can affect other entitlements. How it interacts with the pension lump-sum withdrawal payment, voluntary National Pension enrolment and the My Number card abroad is covered in the guides on those topics.

Common Pitfalls & Regulatory Compliance Risks

• Registering the birth only with the foreign country. Without the reservation, Japanese nationality is lost retroactively.¹
• Counting 3 months as 90 days. The period runs in calendar months from the birth day.²¹⁰
• Applying for a child’s foreign nationality without checking Article 11(1).¹⁵¹⁶
• Quoting the old “age 22” rule. The current deadline is age 20, or 2 years after dual nationality arises after reaching 18.¹³
• Treating the selection declaration as ending, or never affecting, the foreign nationality. Article 16(1) still applies.¹³
• Assuming nothing can happen after the deadline. The duty to choose continues and the Minister may demand a choice under Article 15.¹⁵

See also

Family, education and dual life

• Japanese Embassy Help: Zairyu Todoke, Tabi-Reg & Emergencies: what Japanese embassies and consulates, where birth notifications abroad are filed, can and cannot do for nationals abroad.
• Schooling Abroad: International, Local or Japanese School?: the schooling choices that families raising a dual-national child abroad weigh next.

Foundations and frameworks

• Leaving Japan: Japanese Citizens vs. Foreign Permanent Residents: how the exit and re-entry rules differ for a Japanese child and a foreign-national parent.

Pension and social security

• Voluntary National Pension for Japanese Citizens Living Abroad: the optional pension enrolment open to Japanese citizens living overseas.

Japan exit procedures

• My Number Card When Moving Abroad: Updated 2024–2026 Rules: keeping or obtaining the My Number Card once the family lives outside Japan.

References & Official Sources

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Important Cross-Border Mobility & Compliance Notice

All information presented in this reference publication is compiled from official government authorities, bilateral treaties, and statutory regulations. Cross-border tax obligations, visa eligibilities, pension disbursements, and residency classifications vary significantly based on individual citizenship, financial circumstances, and length of stay. Always seek professional advice from certified tax accountants (Zeirishi), licensed immigration specialists, or competent administrative authorities before taking irrevocable administrative or financial actions.

Footnotes

1. e-Gov Laws (Digital Agency), 国籍法 (Nationality Act, Act No. 147 of 1950), revision in force 1 June 2025, Articles 2, 5, 8, 11 to 18; Supplementary Provisions of Act No. 45 of 1984 Articles 1 and 3; Supplementary Provisions of Act No. 59 of 2018 Articles 1 and 13, accessed October 2026, https://laws.e-gov.go.jp/law/325AC0000000147 (full text via API: https://laws.e-gov.go.jp/api/2/law_data/325AC0000000147) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴ ↩²⁵ ↩²⁶ ↩²⁷ ↩²⁸ ↩²⁹ ↩³⁰ ↩³¹ ↩³² ↩³³ ↩³⁴ ↩³⁵

2. e-Gov Laws (Digital Agency), 戸籍法 (Family Register Act, Act No. 224 of 1947), revision in force 3 September 2026, Articles 13, 25, 29, 40, 43, 49, 52, 102, 103, 104, 104-2, 104-3, 106, 137, 138, accessed October 2026, https://laws.e-gov.go.jp/law/322AC0000000224 (full text via API: https://laws.e-gov.go.jp/api/2/law_data/322AC0000000224) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸

3. Ministry of Justice, Civil Affairs Bureau, 国籍Q&A (Q5, Q6, Q7, Q12 to Q20), accessed October 2026, https://www.moj.go.jp/MINJI/minji78.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴ ↩²⁵ ↩²⁶ ↩²⁷

4. National Diet Library, Diet Record: House of Councillors Cabinet Committee, 9 June 2026, speech 46 (Vice-Minister of Justice), accessed October 2026, https://kokkai.ndl.go.jp/txt/122114889X01420260609/46 ↩

5. Ministry of Justice, Civil Affairs Bureau, 国籍の選択について (sections 1 to 4), accessed October 2026, https://www.moj.go.jp/MINJI/minji06.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

6. National Diet Library, Diet Record: House of Councillors Budget Committee, 17 December 2021, speeches 23, 25 and 27 (MOJ Civil Affairs Bureau Director-General; Minister of Justice), https://kokkai.ndl.go.jp/txt/120715261X00220211217/23 ; https://kokkai.ndl.go.jp/txt/120715261X00220211217/25 ; https://kokkai.ndl.go.jp/txt/120715261X00220211217/27 , accessed October 2026 ↩ ↩²

7. US Government Publishing Office (govinfo), United States Code 2023 edition, Title 8, section 1401 (nationals and citizens at birth), https://www.govinfo.gov/content/pkg/USCODE-2023-title8/html/USCODE-2023-title8-chap12-subchapIII-partI-sec1401.htm ; section 1185(b) (travel documentation of citizens), https://www.govinfo.gov/content/pkg/USCODE-2023-title8/html/USCODE-2023-title8-chap12-subchapII-partII-sec1185.htm , accessed October 2026 ↩ ↩² ↩³

8. Supreme Court of the United States, Trump v. Barbara, No. 25-365, slip opinion decided 30 June 2026 (revised 1 July 2026), syllabus “Held”, accessed October 2026, https://www.supremecourt.gov/opinions/25pdf/25-365_new_5if6.pdf ↩

9. legislation.gov.uk (The National Archives), British Nationality Act 1981, section 2 (acquisition by descent), accessed October 2026, https://www.legislation.gov.uk/ukpga/1981/61/section/2 ↩

10. Consulate-General of Japan in Seattle, 出生届 / Birth Registration (page dated 19 January 2024), web.archive.org snapshot of 12 June 2026, accessed October 2026, https://web.archive.org/web/20260612053126/https://www.seattle.us.emb-japan.go.jp/itpr_ja/00_000126.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

11. Ministry of Justice, 出生届 (procedure guide: period, place, documents), accessed October 2026, https://www.moj.go.jp/ONLINE/FAMILYREGISTER/5-1.html ↩

12. Ministry of Foreign Affairs, press release 「在外公館に戸籍・国籍の届出を行う場合の戸籍謄本の省略について」 (18 March 2024), web.archive.org snapshot of 10 November 2024, accessed October 2026, https://web.archive.org/web/20241110093535/https://www.mofa.go.jp/mofaj/press/release/pressit_000001_00508.html ↩ ↩²

13. National Diet Library, Diet Record: House of Representatives Judicial Affairs Committee, 12 May 2009, speech 39 (government witness, MOJ Civil Affairs Bureau), https://kokkai.ndl.go.jp/txt/117105206X01020090512/39 ; same committee, 17 April 2009, speech 27, https://kokkai.ndl.go.jp/txt/117105206X00620090417/27 , accessed October 2026 ↩

14. US Government Publishing Office (govinfo), United States Code 2023 edition, Title 8, section 1481 (loss of nationality by native-born or naturalized citizen), accessed October 2026, https://www.govinfo.gov/content/pkg/USCODE-2023-title8/html/USCODE-2023-title8-chap12-subchapIII-partIII-sec1481.htm ↩

15. Courts in Japan, Tokyo District Court, 24 June 2016, Heisei 26 (Gyo-U) No. 472, summary, accessed October 2026, https://www.courts.go.jp/hanrei/86272/detail2/index.html ↩ ↩² ↩³ ↩⁴

16. Courts in Japan, Tokyo District Court, 18 February 2021, Heisei 28 (Gyo-U) No. 504, summary, accessed October 2026, https://www.courts.go.jp/hanrei/90756/detail2/index.html ↩ ↩² ↩³ ↩⁴

17. REPORTED (news, not an official source): Bengo4 JP News (弁護士JPニュース), 「国籍選択の機会の不平等」問う違憲訴訟で請求棄却 (17 October 2024), accessed October 2026, https://www.ben54.jp/news/1602 ↩

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