TOKYO - A quarter of Japan's municipalities saw their population decline by more than 10 percent between 2020 and 2025, Kyodo News analysis of census data showed Sunday.
Significant depopulation often leads to a deterioration of public services, prompting some experts to highlight the urgent need to adapt to rapid change.
The number of municipalities experiencing such a decline increased from 247 between 2015 and 2020 to 477, with Suzu, Ishikawa Prefecture, recording the sharpest decline of 34 percent after being hit by a massive earthquake in 2024.
More than half of the municipalities in Iwate and Akita prefectures in northeastern Japan and Kochi Prefecture in western Japan saw such a sharp population decline.
Kyodo News compared preliminary 2025 Census figures as of Oct. 1 with 2020 Census results to analyze population changes in 1,892 municipalities, including 171 administrative districts across 20 government-designated major cities.
The population increased in 243 municipalities. However, in many other municipalities, the rate of population decline cannot be reversed by improvements in the birth rate.
Noting the trend, Kohei Wada, a Chuo University professor specializing in demography, said, "We need to urgently build a society on the premise of population decline in every respect."
Takao Komine, a visiting professor of economic policy at Taisho University, said that in addition to addressing the declining birthrate, adaptive strategies known as "smart shrinkage," such as consolidating infrastructure and reviewing policy spending, are necessary.
"Taking such measures will help maintain and enhance people's well-being," Komine added.
A population decline of more than 10 percent was observed in 97 cities, 294 towns and 85 villages across Japan's 47 prefectures, including Tenryu Ward in Shizuoka Prefecture's Hamamatsu.
Together with Suzu, declines exceeding 20 percent were recorded in three cities, one town and two villages across four prefectures These included the Okinawan village of Tonaki, which experienced a 32.4 percent decline, and Ishikawa's Wajima, which saw a 26.6 percent drop.
In Suzu, maintaining the water pipe network became difficult as many residents moved out after the quake destroyed their homes. Tonaki experienced a similar exodus as public works shrank.
The towns of Okuma, Tomioka, Namie and Naraha in Fukushima Prefecture experienced the highest growth rates -- towns that had been completely evacuated following the Fukushima nuclear crisis in 2011.
Futaba, home to the crisis-stricken Fukushima Daiichi nuclear power plant alongside Okuma, had 211 residents in the 2025 survey, up from zero.
The population grew by more than 15 percent in the Naniwa and Chuo wards of central Osaka, as well as in the Naka ward of central Nagoya. Meanwhile, Shimukappu village in Hokkaido, where the resort industry targeting inbound tourists is booming, experienced a population increase of 13.9 percent.
