Utashinai-shi

In the most recent census the population stood at about three thousand (2,989 in 2020). From 5,941 in 2000, through 5,221 in 2005, 4,387 in 2010, and 3,585 in 2015, it fell to 2,989 in 2020 — about halving in two decades and dropping below three thousand. This is the smallest population among any place that bears the name of a city in the entire country.

Look inside the figures and the striking shape of a valley city after the age of coal emerges. The share of residents aged 65 and over rose from 32.6% in 2000 to 53.3% in 2020, climbing roughly twenty points in two decades to pass the halfway mark — meaning that more than one in two residents is 65 or older. The share of child-rearing households was 8.2% in 2020, the lowest among the eight cities lined up in this article. The employment rate was 40.4% in 2020. Childcare waitlists were zero in both 2024 and 2025. The Fiscal Capacity Index was 0.10 in FY2023, meaning its own tax revenue covers only about one-tenth of expenditure — an extremely deep reliance on the local allocation tax. A valley that once held more than forty thousand, lost its people with the age of coal, and became Japan's smallest city shows this in its numbers. Why it takes this shape cannot be read without tracing the heritage of coal.

The frame of this town rests on a coal valley folded between mountains, the more than forty thousand people at the height of coal, and the end of the age of coal. The first layer is the coal valley. In the mid-Meiji era, the Sorachi colliery was opened in this narrow valley folded between mountains, and people came from all over the country to dig coal. The valley was narrow and flat ground was scarce, yet into that cramped valley a town of pit-mouth dwellings was packed densely. A coal valley folded between mountains — that is the deepest foundation of this town.

At the height of coal, that valley filled with more than forty thousand people. Into the narrow valley came miners and their families, merchants, and carriers, and the valley's life was dyed entirely in coal. But the age of coal did not last long. As the protagonist of energy shifted away from coal, the valley's collieries closed, and the more than forty thousand people drained from the valley like an ebbing tide. The narrow valley folded between mountains had wagered the whole of the town on a single resource — coal — and when that resource departed, it held no other livelihood to fall back on within the valley. In time this valley became the city with the smallest population in the entire country among places bearing the name of a city. The coal valley folded between mountains, the more than forty thousand people, and the end of the age of coal — these three are the very answer to the question of what it means to wager everything a town has on a single resource. Coal called forth forty thousand, and when coal departed the figure fell below three thousand; Utashinai today is set at the floor of that swing.

What marks Utashinai-shi is that a valley swollen to more than forty thousand by coal lost its people as the age of coal departed and became the city with the smallest population in Japan. From 5,941 in 2000 to 2,989 in 2020, it about halved in two decades. Because more than forty thousand people had gathered into a narrow valley folded between mountains relying on a single resource — coal — when that coal departed, people kept leaving the valley with no other livelihood to fall back on. How steep a slope it makes when the whole of a town is wagered on a single resource, and that resource departs — the extreme form of that is on display in this valley. That the share of residents aged 65 and over passed the halfway mark at 53.3% in 2020 — more than one in two residents being 65 or older — is its consequence.

At the same time, childcare waitlists were zero in both 2024 and 2025, and the share of child-rearing households was 8.2% in 2020, the lowest among the eight cities lined up in this article. A Fiscal Capacity Index of 0.10 is a level at which its own tax revenue covers only about one-tenth of expenditure, showing an extremely deep reliance on the local allocation tax. In the valley the coal has left, the lives of the few people who remain and the course of conveying the memory of the colliery do hold the town together, but they fall far short of coal's height of forty thousand and more. The city in the valley the coal has left is now greatly raising the town's age as Japan's smallest city. The population has dropped below three thousand, aging has passed the halfway mark, and fiscal strength is about one-tenth. These three extreme figures are all consequences of the same condition — that people gathered into a narrow valley relying on coal alone. Gazing at any one figure on its own cannot convey the magnitude of this valley's swing.

In Utashinai, both extremes — prosperity and decline — are folded into a single valley. One is the starting point: coal was dug in this narrow valley folded between mountains, and at its height more than forty thousand people pressed in. The other is its character: with the departure of the age of coal it lost its people and became the city with the smallest population in the entire country among places bearing the name of a city. The terrain of a narrow valley folded between mountains gathered people around the pit mouths at the height of coal, but after coal departed it left almost no flat farming land, and no place for another industry, to fall back on within the valley.

In short, Utashinai is a town where a coal valley that once held more than forty thousand became the smallest city in Japan. From a coal valley folded between mountains, to the more than forty thousand people, to the end of the age of coal, to a population that dropped below three thousand — all of it was inscribed by the terrain of "a narrow coal valley folded between mountains." Because the narrow valley held nothing but coal, more than forty thousand people pressed in at its height; by that same narrowness, when coal departed there was no farming land and no place for another industry to fall back on, and the people drained away with no escape. A valley that once pressed in more than forty thousand has now dropped below three thousand and become, among places bearing the name of a city, the one with the fewest people in the entire country — the magnitude of this swing tells the whole of Utashinai.