We sometimes receive inquiries from overseas Nikkei individuals who are unsure whether they hold Japanese nationality, or who do not know how to confirm their nationality status because their Japanese parent has already passed away.
In particular, where a person was separated from their Japanese parent at a young age, or where the Japanese parent is already deceased, the person may have lived overseas for many years without knowing whether they are recorded in a Japanese family register.
In such cases, the first important step is to review the Japanese parent’s family register records from birth to death, including the family register, removed family register, and revised original family register.
Japanese family registers contain important records concerning family status, such as marriage, divorce, the birth of children, acknowledgment of parentage, and filings related to nationality. Therefore, in order to examine the possibility of holding Japanese nationality, it is necessary to trace the Japanese parent’s family register and confirm whether the person is recorded as a child, and whether any birth notification or nationality-related filing was made.
Before the 1985 Amendment: Patrilineal Preferential Nationality by Descent
Under the current Nationality Act of Japan, a child generally acquires Japanese nationality at birth if either the father or the mother is a Japanese national at the time of birth. This is known as the principle of nationality by descent through either parent.
However, before the amended Nationality Act came into effect on January 1, 1985, Japan generally followed the principle of patrilineal preferential nationality by descent, under which a child acquired Japanese nationality when the father was a Japanese national.
As a result, a child born before 1985 to a Japanese mother and a foreign father is highly likely not to have automatically acquired Japanese nationality at birth, even if the mother was Japanese.
On the other hand, a child born to a Japanese father and a foreign mother may have acquired Japanese nationality under the law in force at that time. However, if the child was born outside Japan, it is necessary to individually confirm matters such as whether a birth notification was filed, whether Japanese nationality was reserved, and whether the child acquired a foreign nationality.
Transitional Measures for Acquiring Japanese Nationality
Through the 1985 amendment to the Nationality Act, Japan moved to a system under which nationality could be acquired through either the father or the mother. In connection with this change, transitional measures were established for certain children who had been born before the amended law came into effect to a Japanese mother and a foreign father, and who had been unable to acquire Japanese nationality under the former law.
Specifically, a system was provided under which a child satisfying certain requirements could acquire Japanese nationality by submitting a notification to the Minister of Justice within three years from the date on which the amended law came into effect.
Therefore, for individuals who were minors at the time of the 1985 amendment, whether such a notification was filed during the transitional period is also an important point to confirm when determining whether they hold Japanese nationality.
Whether a person holds Japanese nationality is an important issue that may affect matters such as residence status in Japan, acquisition of a Japanese passport, and proof of family status. For overseas Nikkei individuals who are unsure whether they have Japanese nationality, reviewing the contents of the Japanese parent’s family register is the first step in the investigation.