In a prediction, Professor Hiroshi Yoshida of Tohoku University envisions a future where every Japanese citizen shares the same surname: Sato. This projection, rooted in current social trends, cultural norms, and legal stipulations, suggests a dramatic transformation in Japan over the next five centuries.
Yoshida’s research highlights the growing prevalence of the surname Sato, which is already the most popular surname in Japan. As of March 2023, 1.529% of Japan’s population bore the name Sato, an increase of 0.83% from the previous year. This rise is attributed to the dynamics of marriages, divorces, births, and deaths.
Central to this trend is Article 750 of the Japanese Civil Code, which mandates that married couples adopt one surname, typically the husband’s. This law, a vestige of samurai-era cultural traditions, reinforces the practice of passing family lineage and property through the male line. In 2022, approximately 504,000 couples married in Japan, with 94.7% adopting the husband’s surname. Consequently, the maiden names of around 478,000 women were effectively erased, leading to the gradual disappearance of some ancient family names, especially in cases where the daughter is an only child.
“This is very much part of the cultural heritage of the samurai era in Japan,” Yoshida explains, as reported by the South China Morning Post (SCMP). “In the old days, only a man could be a samurai, and only his son could continue the family name, so women effectively did not have their own names.”
Despite legal provisions allowing couples to choose the woman’s surname, deep-rooted cultural norms result in most opting for the husband’s name. Yoshida attributes this to Japan’s slow progress in gender equality, noting the country has never had a female prime minister.
Yoshida warns that if everyone in Japan eventually shares the surname Sato, it could lead to significant issues. He foresees inconveniences in daily life, a loss of individual identity, and challenges in remembering family and regional histories.
Yoshida is part of the Think Name Project, a group dedicated to addressing the implications of the government’s refusal to allow women to retain their maiden names after marriage. On International Women’s Day, March 8, the group, along with various businesses and social organizations, submitted a petition to the government seeking to amend the law.
However, despite past promises from Japan’s ruling Liberal Democratic Party to examine the issue, meaningful change seems unlikely. The party’s members are predominantly male, elderly, and deeply conservative, showing little real desire for reform. The influential Japanese Trade Union Confederation supports the push for change, with research indicating that over 60% of people would prefer to keep their names after marriage or permit their spouse to do so if selective surnames were legally permitted.
Yoshida’s studies show that if more people were allowed to have different last names, only about 7.96% of Japanese might be named Sato by 2531. Even with this change, the name Sato would still become more common, and by 3310, everyone in Japan might have the last name Sato.
Parallel to the surname study, Yoshida conducted a demographic projection that paints a bleak picture of Japan’s future population. If Japan’s population continues to decline at its current rate, there would only be about 281,866 people in Japan by 2531 and just 22 people by 3310.
This dramatic decline suggests that the Japanese population might disappear entirely before everyone adopts the surname Sato. Additionally, the declining population necessitates strategies to stabilize and sustain the population in the long term.