Nationality Act (Kokuseki Hō)

The Nationality Act (Kokuseki Hō) governs the acquisition and loss of Japanese nationality. Enacted in 1950, the Act establishes the principles of jus sanguinis (citizenship by descent) as the primary basis for Japanese nationality. The Act provides for acquisition by birth to Japanese parents, by birth in Japan in certain circumstances, by naturalisation, and by selection. Loss of nationality is governed by strict rules to avoid statelessness.

Legal area: Law governing the entry, stay, and rights of foreign nationals.

Year enacted: 1950

Full text: https://elaws.e-gov.go.jp/document?lawid=japan-nationality-act

Key Provisions

• Article 2: Acquisition by birth (jus sanguinis)
• Article 3: Acquisition by birth in Japan (jus soli limited)
• Article 5: Naturalisation requirements (residence, conduct, income)
• Article 11: Loss of nationality by voluntary acquisition of foreign nationality
• Article 16: Renunciation of nationality
• Article 17: Prohibition of statelessness

Significance

The Nationality Act reflects Japan’s predominantly jus sanguinis approach to citizenship, with only limited jus soli provisions. Naturalisation requirements have been interpreted strictly by the Ministry of Justice. Japan does not allow dual nationality for adults, requiring renunciation of other nationality upon naturalisation or acquisition. The Act has been criticised for making it difficult for long-term foreign residents to obtain citizenship. The dual nationality prohibition has been challenged on human rights grounds.