Study Warns: All Japanese Citizens Could Share Sato Surname by 2531, But Marriage Would Be Key
A recent study suggests that unless Japan revises its restrictive marriage laws, every citizen in the country could eventually share the same surname. However, this projection might be influenced by the declining marriage rates and the rapidly shrinking population, which could render the issue moot in the long run.
In Japan, unlike most major economies, married couples are legally required to share the same surname, typically adopting the husband’s surname. Same-sex marriages are still not legally recognized in the country, adding to the complexity of the issue. Advocates for women’s rights and proponents of preserving the diversity of Japanese surnames have been calling for changes to these laws to allow couples to maintain both their last names.
According to the study led by economist Hiroshi Yoshida from Tohoku University in Sendai, if the current surname laws persist, all Japanese individuals could bear the surname Sato by the year 2531. Sato is currently the most common surname in Japan, followed by Suzuki and Takahashi, with approximately 1.8 million people having the surname Sato out of the country’s population of 125 million.
Yoshida’s projections, however, are contingent on Japan’s ability to address its declining marriage rate, which has been a significant concern. In 2023, the number of marriages in Japan dropped by nearly 6%, falling below 500,000 for the first time in 90 years, while divorces increased by 2.6% compared to the previous year. Yoshida acknowledged that if the marriage rate continues to decline, his projections could be altered.
Furthermore, Japan is facing a demographic crisis characterized by a rapidly aging population and a declining birth rate. The proportion of elderly individuals aged 65 and above in Japan is at a record high of 29.1%, the highest rate globally. The country’s fertility rate stands at 1.3, well below the 2.1 needed to maintain a stable population without immigration. Prime Minister Fumio Kishida has warned about the impending population crisis, emphasizing its impact on maintaining social functions.
The issue of surname diversity is not unique to Japan, as many East Asian countries also exhibit similar patterns. In China, for example, a significant percentage of the population shares a few common surnames. The phenomenon of surname extinction, known as the Galton-Watson process, is a natural occurrence in patrilineal societies, where surnames are lost over generations as women adopt their husbands’ surnames.
