The public understanding is that dual citizenship is not allowed in Japan: The reality is that dual citizenship (nijyu kokuseki) it is tolerated in some cases and forbidden in other cases which leads to the interpretation that it is neither allowed nor forbidden in current Japanese Nationality Law. The question of dual citizenship becomes a critical one for those in positions and occupations for which the Japanese law explicitly states a Japanese citizenship requirement. One such position is being an elected politician. In 2016, Renho, one of the leading Democratic Party members found herself in a dual citizenship controversy as she did not fully complete the process of resolving her formal dual citizenship status. The Japanese Nationality Law obliges individuals with dual citizenship to make a Declaration of Choice, however when one chooses Japanese as his or her citizenship, there is no requirement to show evidence of citizenship renunciation. This creates a tension between what Faist et al. discuss as de jure intolerance, i.e. restriction to dual citizenship and de facto tolerance, i.e. the actual behaviour of the states. Although there is no law prohibiting dual citizens from running as candidates in elections, the Public Offices Election Act specifically states that only Japanese citizens are eligible to be candidates and official national politicians (see here [in Japanese]). This article will first briefly lay out the legal context, and then give an account to the Renho dual citizenship controversy. After this, we will discuss what citizenship entails in Japan, and what impact the controversy had on the Japanese public.
The legal context
Japan applies the jus sanguinis principle, which is citizenship acquired by descent. Japanese citizenship can only be obtained by parentage and not by birth in the territory. The Nationality Law (see here) states that a person can become a Japanese citizen at birth:
(1) When, at the time of her or his birth, the father or the mother is a Japanese national;
(2) When the father who died prior to the birth of the child was a Japanese national at the time of his death;
(3) When both parents are unknown or have no nationality in a case where the child is born in Japan.
In Article 13 and 14, Japan offers two ways of abandoning a dual citizenship, through the submission of 1) a Notification of Declaration of Choice, or 2) a Notification of Renouncing (ridatsu) Japanese Citizenship. The Declaration of Choice, stating that one chooses Japanese citizenship (Nihon no kokuseki) and will renounce the foreign citizenship, should be made when a dual citizen turns 20 but at the latest at the age of 22. If a second citizenship is not acquired by birth but after turning 20, the Declaration of Choice must be made within 2 years after the person receives a foreign citizenship. The Declaration of Choice is applicable only to those who are born after the 1985 amendment of the law and those who have obtained a foreign or Japanese citizenship out of their own will after 1985. It is assumed that Japanese citizens born before 1985 have chosen Japanese nationality. The Declaration of Choice does not automatically resolve the status of dual citizens, as the Japanese government cannot interfere with foreign countries’ citizenship rules and forcefully withdraw individuals’ foreign citizenship. Article 16 only states that a person who makes the Declaration of Choice needs to “endeavor to deprive himself or herself of the foreign nationality” and there is no obligation to prove whether one really has renounced the foreign citizenship. The law also states that if a Japanese citizen acquires a foreign citizenship out of his or her own free will, she or he loses Japanese citizenship. If a dual citizen fails to report the choice, the state sends a notification and the person in question must respond within a month or otherwise will lose the Japanese citizenship.
The case of Renho’s (dual) citizenship
In 2016, Renho, an influential Democratic Party member, found herself in the middle of a scandal with an allegation that she was a dual citizen. Renho, having a mother who is Japanese and a father who was a citizen of the Republic of China (Taiwan), was born in 1967 as a citizen of the Republic of China. As Japan’s Nationality Law at the time only granted Japanese citizenship to those with a Japanese father or an unmarried Japanese mother, it was not until 1985 when the law was amended to allow all Japanese mothers to pass on Japanese citizenship to their children, that Renho became a citizen of Japan. After she gained power in politics and in the Democratic Party, critics argued that Renho had failed to complete a Declaration of Choice at the age of 22. Renho responded to the scandal by reporting to the Taiwanese embassy her renunciation of citizenship; however, in summer 2017, as public mistrust of Renho’s citizenship was still ongoing, she was forced to make an unprecedented action as the head of Democratic Party; to disclose her koseki (family registration) to prove that she is a Japanese citizen.
Renho’s case does not represent the real issues that most people who possess dual citizenship face. However, it did grab the attention of the general Japanese public on the issue of dual citizenship. Being a dual citizen and a politician raises certain levels of concern in many countries. Renho’s ambiguous state was treated as a problem not only by the conservative media and politicians from the ruling government, but also within her own party, which resulted in her resignation as the party leader later in the summer of 2017. A conservative private media outlet treated Renho, a potential dual citizen, as a “spy”. Even her choice to be an active politician with her Chinese name became the subject of critique. Renho’s case provides a good example of how people with dual citizenship from countries where political tensions exist are treated and perceived by the public. Moreover, the controversy over Renho’s dual citizenship seemed to be far more complex than just a legal issue, highlighting how the Japanese public is not ready for a female leader, and a person with a migrant background and mixed roots, to lead the political arena.
De jure and de facto acceptance
Japan’s ius sanguinis citizenship rule is not unique compared to other countries. This current de iure intolerance and de facto tolerance caused by the law not prohibiting but yet not allowing dual citizenship emerged in the process of adding the provision on renunciation, which was imposed by diplomatic reasons. The current Japanese Constitution came into force in 1947, and the Japanese government chose to translate the word drafted as “people of Japan (jinmin)” by GHQ (General Headquarters)/SCAP (Supreme Commander for the Allied Powers) as “Japanese national (kokumin)”. What was interesting in the process of establishing the Constitution was that the people from the Korean Peninsula and Taiwan, the former colonies of Japan, who in the past were treated as “subjects” and included as “people of the empire of Japan” were now excluded from the concept of “people of Japan” through introducing the concept of “national (kokumin)” In Japan, nationality and citizenship, and the emotions attached to them, are inseparable. This is because the idea of being Japanese and being a Japanese citizen is based on the visible differences which can be physical appearance or ethnic names, and idea of culture which includes language and behavioural norms. The Renho controversy became one of the examples of how an ethnic sounding name can become a target of criticism and a question of loyalty by a Japanese citizen.
Even though foreign citizens in Japan are, in the majority of the cases, provided with rights to healthcare, social security, social welfare, education and employment by the local authorities, the current Constitution states that rights to access these services are the rights of Japanese citizens. Local authorities need to follow the standard procedures for Japanese citizens and permanent residents equally, which means that even though children with non-Japanese citizenship have access to education as well as families with refugee backgrounds to social welfare in most of the cases, it is up to each local authority’s discretion to decide whether to provide these services and to what extent. Public assistance is one such right that the local authorities have been providing to a large extent even though the law excludes non-citizens from accessing. The ruling by the Supreme Court on July 18th, 2014 stating that “foreigners who possess permanent residency in Japan” do not have the legal right to public assistance under the Public Assistance Law as they are not citizens made it clear that permanent residents who are non-citizens may be denied access. Therefore, for the increasing number of foreign workers who reside in Japan permanently, the issue of citizenship is a critical one which may affect their own and their children’s lives as well as social security in Japan.
For Japanese persons living overseas, citizenship can have a huge impact on the level of access to rights, such as voting, in the country of residence. In a context of globalization and growing migration, the Japanese Nationality Law comes into stark conflict with other developed countries’ policies which are moving towards toleration of dual citizenship. Only about 1.9% of the population residing in Japan possess foreign citizenship, which does not motivate the discussion and awareness of dual citizenships. It is not clear how many persons are overall dual citizens with a Japanese nationality since dual citizenships, both overseas and within Japan, are not registered and the potential population is only registered as Japanese. This practice of not registering dual citizenships also creates de facto tolerance.
Where to go from here?
It is not surprising that the de facto tolerance leads Japanese to keep their dual citizenships openly or in secrecy. In the midst of the Renho controversy, another politician, Kimi Onoda, was also scrutinized and revealed to have been a dual citizen. Onoda, an upcoming member of the ruling Liberal Democratic Party and an Upper House lawmaker who was born in the US to an American father and a Japanese mother, immediately responded to the accusation by making the Declaration of Choice and proceeding with the renunciation of her American citizenship by reporting to the embassy.
The Ministry of Justice recently announced that the number of foreign citizens residing in Japan on a long term basis is reaching around 2 millions, which is a record high in Japan’s history. The Ministry of Justice also reported in November 2017 that that the number of Declaration of Choice notifications for the 2016 fiscal year hit the record high of 3368, with an increase of more than 500 since 2015. The number of Renunciation of Foreign Citizenship notifications was 150. These notifications have also steadily increased in the past decades, from 1570 for notifications of Declaration of Choice and 21 for notifications of Renunciation of Foreign Citizenship in 2006. The Renho dual citizenship controversy not only made the public and the political world aware of the fact that there are de facto dual citizens in Japan, the controversy also revealed confusions around what the Nationality Law actually states. The reactions from the public and the current political climate indicate that Japan probably will maintain its ius sanguinis citizenship rule. The question is which direction the Japanese government will take from now on to resolve or maintain the de jure intolerance and de facto tolerance towards dual citizenships.
The Japanese Government does not use the term citizenship but only uses the term nationality in the English translation of the constitution. When the article refers to the law itself the term nationality is used.
 Faist, Thomas, et al. “Dual Citizenship as a Path-Dependent Process.” International Migration Review, vol. 38, no. 3, 2004, pp. 913–944.
 Japanese immigration to the US in late 19th and early 20th century led to American citizens being born to Japanese couples, which caused tensions in the US which country these Japanese-Americans will be more loyal to, which led the US government to push the Japanese Government to introduce the requirement to choose. A historical overview and detailed discussions on Japanese Nationality Law can be found in William Wetherall. “Nationality in Japan” in Japan’s Diversity Dilemmas: Ethnicity Citizenship and Education. 2006.
 It should be noted that the Korean governments also supported this move, and there are different positions and debates around this choice made by the Japanese and Korean governments to exclude Koreans in Japan from being Japanese citizens.
 Kashiwazaki, Chikako. “The Foreigner Category of Koreans in Japan: Opportunities and Constraints” in Diaspora without Homeland: Being Korean in Japan. 2009.
 One of the debated areas is for example is providing Japanese language education and support for children who do not speak Japanese as their mother tongue.
 Court Case Heisei 24 (Gyou Hi) Dai 45.
 Ministry of Justice, e-stat 2017. http://www.e-stat.go.jp/SG1/estat/List.do?lid=000001196143