Japan’s Ministry of Internal Affairs and Communications released preliminary figures from the 2025 census on May 29, showing that as of October 1, 2025, Japan’s total population, including foreign residents, stood at 123,049,524. This represents a decrease of approximately 3.097 million people, or 2.5%, compared to the 2020 census — the largest decline since the population began to shrink continuously in 2015. Among the 47 prefectures, only Tokyo (up 1.4%) and Okinawa (up 0.1%) saw population increases, while the remaining 45 all experienced declines. Akita Prefecture recorded the largest drop at 8.1%, followed by Aomori at 7.9%. Saitama and Chiba prefectures saw their populations decrease for the first time since statistical records began in 1920. The combined population of the four prefectures of Tokyo, Kanagawa, Saitama, and Chiba was approximately 36.986 million, accounting for 30.1% of the national total — the first time this figure has exceeded 30%, highlighting the continued intensification of the single-polar concentration trend.
The ministry attributed the main cause to an expanding „natural decrease,“ where deaths continuously outnumber births due to an accelerating decline in birth rates and an aging population. At the municipal level, 1,558 of the country’s 1,719 municipalities (90.6%) saw population declines, with more than a quarter experiencing decreases of over 10%. The number of households nationwide increased by 2.3% to 57,124,507, but the average number of people per household fell to 2.15, the lowest since 1970, reflecting the structural change of a growing number of elderly single-person households. According to UN projections, Japan, China, Russia, and Thailand are among the top 20 countries experiencing population declines between 2020 and 2025, with Japan seeing the largest decrease.