Citizenship in Japan

Naturalisation timelines, tests, and dual nationality

Naturalisation is governed by the Nationality Act and administered by the Legal Affairs Bureau rather than the immigration authorities. The ordinary requirement is around five years of continuous residence with lawful status, sufficient means, good conduct, and capacity — and Japan does not permit adults to hold dual nationality, so the original citizenship generally has to be given up.

The conditions in outline

• Around five years of continuous residence in Japan, with a lawful status of residence throughout.
• Being of legal adult age under both Japanese law and, in principle, the law of the applicant's own country.
• Good conduct, assessed broadly and including tax compliance and driving record.
• The ability to make a living, whether through the applicant's own means or those of a spouse or relative in the same household.
• Loss or renunciation of the existing nationality on acquiring Japanese nationality.
• No history of advocating or belonging to organisations seeking to overthrow the constitutional order.

Naturalisation is not the same process as permanent residence

The two are handled by different arms of government and the paperwork differs greatly in character. Naturalisation is document-heavy in a way that surprises most applicants: family registers or their equivalent from the country of origin, a detailed account of the applicant's life and household, employment and income records, and often a hand-drawn map of the home and workplace.

Applications are filed and discussed in Japanese, and interviews are conducted in Japanese. Written and spoken ability is assessed, commonly described as being around the level expected of a Japanese primary school pupil in the middle grades.

Processing is generally measured in many months, with the Legal Affairs Bureau commonly holding several meetings with the applicant before the file is formally accepted.

The dual nationality question

Japanese law requires an adult naturalising to give up the previous nationality, and separately requires Japanese nationals who acquire another nationality by their own choice to choose between the two. Some countries make renunciation straightforward; others make it slow, expensive, or in a few cases practically impossible, which affects the timetable more than anything on the Japanese side.

Children born with more than one nationality are permitted to hold both until a published age, at which point a declaration of choice is required. This is an area of continuing legal debate in Japan and the practical enforcement has historically been uneven.

Birth and descent

Nationality in Japan follows descent rather than place of birth. A child born in Japan to two foreign parents does not acquire Japanese nationality by that fact alone, whereas a child with a Japanese parent generally does, subject to the acknowledgement and registration rules that apply where the parents are not married.

Official sources

• Ministry of Justice — nationality
• Immigration Services Agency

Checked against these pages in September 2026. Fees and processing times change without notice — confirm before you act.

More on Japan