2025-05-22

International marriages are increasing in Japan, and children born to such couples, so-called “half-borns,” are not uncommon. Surprisingly, it is not well known how the nationality of a half-born child is determined. Here, we will explain some of the issues related to the nationality of half-breeds.

What is the nationality of a half-born child?

The nationality of a child born to a Japanese parent and a foreign parent is Japanese nationality. In Japan, even if a child is born abroad, if one of the parents has Japanese nationality, the child will unconditionally acquire Japanese nationality.

On the other hand, in the U.S., a child born in the U.S. can acquire U.S. citizenship unconditionally, regardless of the nationality of the parents.

Problem of Dual Citizenship

For example, a child born to a Japanese citizen husband and an American citizen wife can acquire Japanese citizenship, but if the child is born in the U.S., he or she will also acquire American citizenship. This is commonly referred to as “dual nationality.

If a child with dual citizenship returns to Japan, he or she can live with his or her dual citizenship for the time being. However, they must choose their nationality before the expiration of a certain period, as described below.

Choice of Nationality

According to “Article 14, Paragraph 1 of the Nationality Law,” a person who has both Japanese and foreign nationality (dual nationality holder) must choose one of the two nationalities by a certain deadline. Even if the deadline has passed, the person must still choose one of the two nationalities.

If a person does not choose Japanese nationality after a certain period of time, the Minister of Justice can demand that he or she do so. If the person is not selected within one month, he or she loses Japanese nationality and becomes a foreign national only. In other words, Japan recognizes only one nationality.

So when is this “fixed deadline”? According to the Nationality Law, a person must choose his or her nationality by the age of 20 if he or she became a multiple national before reaching 18 years of age, or within two years of becoming a multiple national if he or she became a multiple national after reaching 18 years of age.

Previously, the age of majority was 20, so the deadline was “until the age of 22 if one became a multiple national before reaching 20, or within 2 years of becoming a multiple national if one became a multiple national after reaching 20. The current age has been changed to 18 since the age of adulthood was reduced to 18 in April 2022.

The following methods are available for selecting nationality. However, if the person concerned is under 15 years of age, a legal representative (such as a person with parental authority) must do so on his/her behalf.

The first method is to select Japanese nationality by completing the procedures for renunciation in accordance with the laws and regulations of the foreign country and submitting a “notification of loss of foreign nationality” to the municipal office or Japanese embassy, etc. The second method is to submit a “notification of selection of nationality” to the municipal office or Japanese embassy to the effect of selecting Japanese nationality and renouncing the foreign country’s nationality. The second method is to submit a “notification of selection of nationality” to the municipal office or Japanese embassy.

The second method is to submit a notification of renunciation of nationality to the municipal office or Japanese embassy, etc., attaching a document certifying that you have selected a foreign nationality. The second method is to submit a “notification of loss of nationality” to the municipal office or Japanese embassy, etc., attaching a document proving that you have chosen foreign nationality.

Conclusion

A child born abroad to one parent who is a Japanese citizen is considered to have “dual nationality. For the time being, there is no problem in living in Japan, but the child must choose which nationality to choose by the age of 18.