A recent study has suggested that unless married couples are allowed to use separate surnames, all Japanese citizens will share the same family name within 500 years. This study, led by Hiroshi Yoshida, an economics professor at Tohoku University, forms part of a campaign advocating for updates to a civil code established in the late 1800s.
Yoshida’s projections indicate that if Japan maintains its current policy of requiring couples to adopt a single surname, every Japanese individual will bear the name “Sato” by the year 2531. While acknowledging the speculative nature of these projections, Yoshida aims to highlight the potential societal impacts of the current surname system using numerical data.
He warns that a nation where everyone shares the same surname would lead to individuals being addressed by their first names or numerical identifiers, which he deems undesirable. “Sato” already stands as the most common surname in Japan, representing 1.5% of the population according to a March 2023 survey, closely followed by “Suzuki.”
Despite initial skepticism from some social media users who mistook the study for an April Fools’ Day joke, Yoshida emphasizes the importance of the issue and hopes to prompt serious consideration.
Yoshida’s calculations project that without changes to surname laws, the percentage of Japanese individuals named “Sato” will steadily increase, reaching 100% by 2531. Currently, when Japanese couples marry, they must decide on a shared surname, a decision that typically results in the woman adopting her husband’s surname in 95% of cases.
However, if the government were to yield to growing pressure to permit separate surnames for married couples, the study suggests a different outcome. An alternative scenario, based on a survey indicating a desire among 39.3% of respondents to share surnames even with the option of using separate ones, forecasts a significant decrease in the prevalence of the surname “Sato” by 2531.
Advocacy groups pushing for a change in surname laws see potential in this issue to gain traction, as it could lead to the preservation of diverse family and regional identities. Despite some resistance from conservative factions within the ruling Liberal Democratic Party, who argue that changing the law would disrupt family unity and confuse children, there is momentum behind the movement for reform.