Photo/Illutration (asahi shimbun)


A study has found that unless Japan starts allowing married couples to have separate surnames, all Japanese people will share the same family name of Sato in about 500 years.

The number of surnames in Japan is decreasing every year due to the country’s unique law that requires married couples to share the same surname.

Everyone having the same surname “will not only be inconvenient but also undermine individual dignity,” said Yoshida. “This would also lead to the loss of family and regional heritage associated with surnames.”

About 500,000 couples wed annually in Japan, with nearly 95 percent of all brides taking their husbands’ surnames.

According to the study, the most common surname in Japan currently is Sato, which accounts for 1.5 percent of the population.

The study, conducted as part of a campaign to raise awareness about the issue of married names, found that the proportion of people with the surname Sato increased by 0.83 percent between 2022 and 2023.

If the current rule of married couples sharing the same surname persists, and the number of people named Sato continues to grow at this rate, then half of the Japanese population will be Sato in 2446, and eventually, 100 percent of the population will have the surname in 2531.