On 8 March 2024, 12 men and women filed a lawsuit at the Tokyo and Sapporo District Courts. They claimed that the provisions of the Civil Code and Family Register Law — which do not allow married couples to choose separate surnames — violates Japan’s Constitution, as Article 24 guarantees ‘freedom of marriage’. 

Similar lawsuits have captured public attention in the past. The Supreme Court’s Grand Bench ruled in 2015 and 2021 that the current system is ‘constitutional’. The plaintiffs argue that changing surnames results in a loss of identity and honour. They also claim that Article 750 of the Civil Code, which requires couples to have the same surname, and Article 74 of the Family Register Law, which sets out the procedures for marriage registration, have ‘neither necessity nor rationality’. 

Article 750 says that ‘[a] husband and wife shall adopt the surname of the husband or wife … at the time of marriage’. This system is male-dominant. According to the Cabinet Office, of the approximately 480,000 couples who legally married in 2022, about 95 per cent changed their surname to that of the husband. 

The Japanese system, where married couples must choose one surname, is rare. The United Nations has advised Japan to make corrections three times, so that women are able to keep their original surnames. Major countries that allow the selective use of separate surnames include the United States, the United Kingdom and Australia. France, South Korea and China follow the ‘principle of separate surnames’. Thailand, Italy and Turkey allow combined surnames.

In Japan, it is not historically customary for spouses to share the same surname. The legal use of separated surnames traces back to the establishment of rules governing the surnames of married couples in the Japanese Civil Code of 1876. Influenced by the practices of the samurai class, the custom of maintaining separate surnames for spouses was introduced during this period.

During the Edo period (1603–1867), farmers and townsmen were not allowed to have surnames. Women from samurai families who had surnames during the Edo period continued to use their maiden surnames even after marriage.

For building a modern nation — since using only one’s given name was insufficient for identifying citizens — the Ordinance of Civil Names for Commoners was issued in 1875, requiring everyone, including women, to have surnames. It was believed that surnames should indicate a person’s family of origin. This led to the notion that separate surnames for spouses were natural.

But in 1898, under the influence of the then-prevailing Western idea of ‘conjugal unity’, the government enacted the Civil Code, which stipulated that ‘a wife, through marriage, enters her husband’s household and adopts his surname’.

Throughout the late 19th and 20th centuries, nationalism — the dominant ideology — was intertwined with the family system. Nationalism underlies the emotional resistance to the option of separate surnames for spouses. Though the legal compulsion to take on the husband’s surname was removed in the 1947 Amendment to the Civil Code after World War Two, the system of spousal surnames being the same has persisted.

Advocacy for the legalisation of selective separate surnames for spouses gained momentum ’in 1975 and peaked in the 1980s with the enactment of the Equal Employment Opportunity Law and the ratification of the Convention on the Elimination of All Forms of Discrimination against Women. 

In 1996, the Legislative Council recommended a revision to the Civil Code, including the introduction of selective separate surnames for spouses. But it was not submitted to the Diet due to opposition from Liberal Democratic Party members.

A survey by the Cabinet Office in December 2017 found that 29.3 per cent of respondents opposed the statement ‘couples should always use the same surname’, while 42.5 per cent agreed with the legal amendment towards introducing the selective separate surname system, surpassing opponents by more than 10 percentage points. 

In a July 2022 survey by the Ministry of Health, Labour and Welfare, the percentage of those in favour of ‘not requiring the same surname and allowing different surnames’ reached 61 per cent. Still, the Fifth Basic Plan for Gender Equality, adopted by the Cabinet in 2020, had the phrase ‘selective separate surname’ removed due to opposition from the Liberal Democratic Party. 

The debate within the Liberal Democratic Party regarding selective separate surnames for married couples is at a deadlock, with opponents arguing that allowing separate surnames for married couples would result in the loss of Japan’s traditional family bonds. This view was particularly strong among conservative organisations, including the largest right-wing group, Nippon Kaigi, of which nearly half of Japan’s parliamentarians are members. 

Japan should reassess its policies and legal systems, with due consideration for gender balance in politics and the judiciary. Introducing a legal framework for selective separate surnames represents an initial stride towards gender equality. The implementation of selective separate surnames poses a complex challenge for Japan.

Yasuo Takao is Adjunct Senior Research Fellow at the School of Media, Creative Arts and Social Inquiry at Curtin University.