Oda-shi

In the most recent Population Census the population is about 33,000 (32,846 in 2020). This city’s population carries a step from a merger. In 2005 the former Ota City merged with Yunotsu Town and Nima Town to form its present limits. Before the merger, 2000 was 33,609 for the former Ota City; with the two towns added, 2005 was 40,703, and from there it fell gently but steadily after the merger — to 37,996 in 2010, 35,166 in 2015, and 32,846 in 2020.

Looking inside the figures, as is typical of a San’in city, aging runs deep. The share aged 65 and over rose from 29.3% in 2000 to 40.4% in 2020, passing four in ten. Households with children make up 17.8% (2020), and the childcare waitlist was zero in both 2024 and 2025. The Fiscal Capacity Index was 0.30 in fiscal 2023 — its own tax revenue covers only about three-tenths of expenditure, with a very large dependence on the allocation tax. The figure shows the town of the silver mine losing population and deepening in age after the merger, while holding the childcare waitlist at zero. Why it takes this shape cannot be read without tracing the history of Iwami Ginzan.

Ota’s skeleton is set by the geography of a mountainous land facing the Sea of Japan, and by the silver those mountains held. The old layer is Iwami Ginzan. Said to have been developed by Kamiya Jutei in 1526, this silver mine boasted one of Japan’s largest outputs from the Warring States period into the Edo era. The silver mined here is said to have crossed the sea and circulated widely, and its name is inscribed in the history of the world’s silver. Omori, the center of the silver mine, was governed in the Edo era as territory directly held by the shogunate, and an old townscape still remains there as an Important Preservation District for Groups of Traditional Buildings.

This silver mine ended its role in the modern era. As the veins ran out, the mine closed entirely in the 1920s. Yet its remains and townscape, and the air of Yunotsu — the port town that shipped out the silver — kept their cultural value. In 2007 these were inscribed as “Iwami Ginzan Silver Mine and its Cultural Landscape” on the World Cultural Heritage list, valued as the figure of a mine in harmony with nature, from the mining of the silver to its shipping out. Mount Sanbe, which appears in the kuni-biki land-pulling myth, also rises within the city. Producing some of the world’s largest output of silver, governed as shogunate territory, and inscribed as World Heritage — this town’s form stands on the history of the silver held by a mountainous land facing the Sea of Japan.

What characterizes Ota-shi is that, while carrying the history of a World Heritage silver mine, it has lost much of its population and deepened in age after the merger. From the 40,703 of 2005, with the two towns added, to the 32,846 of 2020, it lost some eight thousand over fifteen years. In central San’in, a land at a distance from Matsue and Hiroshima, the flow of younger generations moving to the cities is strong, and one can read population loss and deepening age advancing together. That the share aged 65 and over reached 40.4% in 2020, passing four in ten, is the sign of that contraction.

That contraction shows in the fiscal figures too. A fiscal capacity of 0.30 is a level whose own tax revenue covers only about three-tenths of expenditure, with a very large dependence on the allocation tax — mirroring that, against the expenditure of supporting a wide, mountainous municipality, the tax base of a town built on tourism and local industry has its limits. Even so, the childcare waitlist has held at zero, and the childcare supply against a falling population reads as maintained. The standing of World Heritage and the reality of losing much population coexist in one town. The town of the silver mine now loses much population and deepens in age after the merger, while holding the waitlist at zero and supporting its finances strongly with the allocation tax. The population has fallen greatly, aging has passed four in ten, and fiscal strength is weak. That this single land holds these two figures of such different magnitude — the standing of World Heritage and the reality of a 0.30 fiscal capacity — is the premise one cannot leave out when reading Ota’s numbers.

In Ota, roles brought by silver fold over one another. One is the history of Iwami Ginzan, opened in 1526 and boasting one of the world’s largest outputs — an old layer with a name inscribed in the history of the world’s silver. Another is the townscape of Omori, governed as shogunate territory, and Yunotsu hot spring, which shipped out the silver, both keeping the character of an Important Preservation District for Groups of Traditional Buildings. And the World Heritage “Iwami Ginzan Silver Mine and its Cultural Landscape,” inscribed in 2007, gives this town the distinctive structure of a mining landscape in harmony with nature.

That a mountainous land facing the Sea of Japan held silver gave rise to the world-class silver mine opened in 1526, nurtured the townscape of Omori under shogunate rule and Yunotsu hot spring that shipped out the silver, and led to the 2007 World Heritage inscription. That same mountainous land now holds an aging rate past four in ten and a contracting population. Central San’in, mountains that produced silver — the standing of World Heritage and the reality of contraction overlap at the same single point. That is where Ota stands now.