Everyone in Japan could have same surname 'Sato' by 2531, simulation reveals

A simulation run by Japanese professor Hiroshi Yoshida revealed that by the year 2531 everyone in Japan will have the surname Sato. The simulation is based on Japan's rule that legally requires married couples to share the same surname. Sato is already the most-used surname in Japan, accounting for 1.5% of the total population as per a March 2023 survey.