Not to accept dual citizenship “does not violate the Constitution” - Supreme Court dismisses appeal

Recently NHK News on-line reported the following:

二重国籍認めないのは“憲法に違反せず” 上告退け確定 最高裁

2023年10月2日 17時52分

みずからの希望で外国の国籍を取得すると、日本国籍を失い、二重国籍が認められない国籍法の規定が憲法違反かどうかが争われた裁判で、最高裁判所は2日までに原告側の上告を退ける決定をし、「憲法に違反しない」とした判決が確定しました。

日本の国籍法は、外国の国籍をみずからの希望で取得した場合、日本国籍を失うと規定していて、二重国籍を認めていません。

これについて、スイスやリヒテンシュタインに住み、現地の国籍を取得して日本国籍を失った人など、8人は「意思に反して国籍を奪う法律の規定は個人の尊重を定めた憲法に違反し、無効だ」と主張して、国に日本国籍があることの確認と賠償を求めました。

2審の東京高等裁判所はことし2月、「複数の国籍を認めると、どの国が個人を保護するかをめぐって国家間の摩擦が生じたり、納税や兵役などの義務について矛盾が生じたりするおそれがある。国籍法の規定は、その原因となる二重国籍をできるかぎり防ぎつつ、国籍を変更する自由を保障していて合理的だ」として、1審に続いて憲法違反ではないと判断して、訴えを退けました。

原告側は上告していましたが、最高裁判所第1小法廷の岡正晶裁判長は、2日までに上告を退ける決定をし、国籍法の規定は「憲法に違反しない」とした判決が確定しました。

Translation

On the 2nd the Supreme Court ruled against a plaintiff's appeal in a case regarding whether the provision of the Nationality Act which prohibited dual nationality was a violation of the Constitution in case when one acquired a foreign nationality based on one's own wishes, one would lose the Japanese nationality as the same time; the ruling confirmed that “this does not violate the Constitution.”

Under the Japan's Nationality Law, if a person acquired foreign nationality of their own choice, one would lose the Japanese nationality, and dual nationality was not allowed.

Regarding this, eight people, including those who lived in Switzerland and Liechtenstein, in losing their Japanese nationality after acquiring local nationality, suggested said, ``The provision of the law, that deprives people of their nationality against their will, has violated the constitution which stipulates respect for individuals and is thus invalid''; and demanded the country to confirmation their Japanese nationality and compensation.

In February this year, the Tokyo High Court which ruled on the second instance and stated, ``Recognizing multiple nationalities may cause friction between countries over which country will protect the individual, or there may be conflicts regarding obligations such as tax payments and military service. The provisions of the Nationality Act are reasonable because they guarantee the freedom to change nationality while preventing dual nationality.” Following the first instance, the lawsuit was dismissed, and ruled that there was no violation of the constitution.

The plaintiffs filed an appeal, but Chief Justice Masaaki Oka of the First Petty Bench of the Supreme Court decided to dismiss the appeal on the 2nd, and ruled that the provisions of the Nationality Act "does not violate the Constitution."

So, in Japan the Nationality Act prohibits dual nationality.