All Japanese people will likely have the same surname Sato by 2531

According to a study, all Japanese people will have the same surname Sato by 2531 if the country maintains the rule that husband and wife must use the same surname after marriage.

According to the head of the study, Professor Hiroshi Yoshida at Tohoku University's Center for Economic and Social Research on Aging, as of 2023, Sato is currently the most common surname in Japan with 1,529% of Japanese people carrying this family .

Professor Hiroshi Yoshida of Tohoku University's Center for Economic and Social Research on the Aging presented his research on them in Japan, March 22, 2024. (Photo: Mainichi).

Professor Yoshida conducted research and calculated two scenarios:  one is that Japan maintains a common surname system between married couples and the other is that  it applies a separate, selective surname system.

He used data available on the website Myoji-yurai.net, which provides name-related information based on government statistics and phone directories. Based on the trend in the number of people with the surname Sato, he calculated the proportion of the Japanese population with this surname and the estimated rate of increase.

Professor Yoshida's calculation results show that, under the current system where spouses will have to change to the same surname after marriage, the proportion of the Japanese population with the surname Sato has increased 1.0083 times from 2022 to 2023.

Assuming the above growth rate remains constant and couples called Mr. Sato and Mrs. Sato continue to increase every year, more than half the population will have the last name Sato by 2446. By 2531, all everyone will have the last name Sato.

According to a 2022 survey by the Japan Confederation of Trade Unions of 1,000 workers aged 20 to 59, 39.3% of single people said they would like to have the same surname as their spouse even if the surname system was adopted. selectively private. Using this number, Mr. Yoshida determined that by 2531, only 7.96% of the population will be named Sato under the selective family system, but the Sato family will continue to dominate in 2015. 3310.

At the same time, if Japan's population continues to decline at the current rate, there will be only 22 people left by the year 3310. Mr. Yoshida concluded that if a separate family system is applied, the diversity of Japanese surnames will increase. will be maintained until the population completely disappears.

After centuries of custom that husband and wife must share the same surname, waves of protest and desire to keep separate surnames have begun to appear in Japanese society.

Professor Yoshida emphasized that his aforementioned estimate was made based on a hypothetical scenario and commented: "I sympathize with their goal in bringing issues related to their own system. selective about numbers. If everyone had the last name Sato, we would most likely have to be called by our first names or by numbers. And I think that's not a good thing . "