Everyone in Japan will have the same surname by 2531 unless laws are changed to allow married couples to have different names, according to a new study.

Sato is the most popular family name in Japan, shared by 1.5% of the population.

The study, led by Hiroshi Yoshida, a professor at Tohoku University, projects that will rise to 100% in just over 500 years if there is no change to legislation which currently requires married couples to take either the husband or wife’s last name.

Prof Yoshida stressed his estimate was “mechanically calculated based on an assumed scenario”, according to Japanese newspaper The Mainichi.

But he added: “If everyone becomes Sato, we may have to be addressed by our first names or by numbers.

“I don’t think we can call that a good world to live in.”

According to the research, the proportion of Japanese named Sato increased 1.0083 times from 2022 to 2023.

If that rate remains constant – with no change to the law – half of the Japanese population will share that name in 2446, rising to 100% in 2531.

Prof Yoshida said everyone having the same surname “will not only be inconvenient but also undermine individual dignity,” according to Japanese newspaper Asahi Shimbun.

“This would also lead to the loss of family and regional heritage associated with surnames.”

Read more from Sky News:
Trillions of bugs to emerge ‘in biggest invasion in centuries’
Gang war turns ‘peaceful’ European country into murder hotspot

Keep up with all the latest news from the UK and around the world by following Sky News

The study was commissioned by the Think Name Project and other organisations that want Japan’s laws to change so couples can choose to have different surnames.

Japan is the only country in the world that requires married couples to use the same name.

Under a scenario where couples were allowed to take different names, Prof Yoshida forecast 8% of people would be called Sato by 2531.

He modelled this on a 2022 survey by the Japanese Trade Union Confederation, which found 39.3% of respondents wanted to share a surname, even if they had the option of using separate ones.

Related posts:

In the nation where COVID first gripped Europe, fans are optimistic of a safe and successful Euros Earth is home to 14% more tree species than previously thought ‘Real threat of nuclear danger’: Ukrainian power plant ablaze after coming under attack from Russia ‘More deaths, more suffering and more destruction’ to come in Ukraine – NATO Squid Game season two is on the way – and we’ll meet Young-hee’s boyfriend An easy mistake? Artwork hung upside down for 75 years Female referee to take charge of men’s World Cup match for first time Italy to introduce entry fee for ancient Roman Pantheon Another night of looting and lawlessness – and nobody knows what will happen next ‘I’ll put a bullet in your head’: Witness says French police threatened teen before fatal shooting Russia pulls out of fishing deal and tells Britons to ‘lose weight’ Some signs Leo Varadkar planned to step down after black eye for government