Satsumasendai-shi

In the 2020 Population Census the population is 92,403 — about ninety-two thousand. This city was born in 2004 by the new merger of the former Sendai City with surrounding towns and villages. From the 102,370 of 2005, when data can be taken, it has gently lost some ten thousand over fifteen years, to 99,589 in 2010, 96,076 in 2015, and 92,403 in 2020. It is the curve of a town that opened onto the basin of the second-largest river in Kyushu, shrinking gently.

Looking inside, the figure of a city of the northwest of Kagoshima Prefecture appears. The share aged 65 and over rose from 25.9% in 2005 to 32.1% in 2020, passing three in ten. The household-with-children share is 19.8% in 2020, and the Childcare Waitlist was zero in both 2024 and 2025. The Fiscal Capacity Index was 0.59 in fiscal 2023 — a level able to cover about six-tenths of expenditure with its own tax revenue, in the middle rank for a regional city. The figure shows in the numbers: the center of ancient Satsuma, losing population and deepening its aging after the merger while keeping its fiscal strength in the middle rank. Why it takes this form cannot be read without going back to the past of the center of ancient Satsuma and the outlying islands.

Satsumasendai’s frame is set by the geography of the basin of the Sendai River, the second-largest river in Kyushu, and by the past in which, from antiquity, this land was the center of Satsuma. The old layer is the centrality of antiquity. From within the city have been found the ruins of the provincial seat that was the provincial office of the ancient province of Satsuma, and the ruins of a Kokubunji (provincial temple). In antiquity, this land was the center of the politics and culture of the province of Satsuma. It was the pivotal land of Satsuma, reached early by the influence of the central government.

And in the present, this wide city area holds a river, the sea and a power plant. In 2004, the former Sendai City and Hiwaki, Iriki, Togo and Kedoin Towns, together with Sato, Kamikoshiki, Shimokoshiki and Kashima Villages — one city, four towns and four villages — merged anew, and the present Satsumasendai City was born. By this merger, the whole of the Koshikijima Islands, made up of Kami-Koshiki, Naka-Koshiki and Shimo-Koshiki Islands stringing together offshore, was added to the city area. Also, at Kuminzaki at the tip of a peninsula, Kyushu Electric Power’s Sendai Nuclear Power Plant is sited, bearing a wing of the regional economy. Being the center of ancient Satsuma, holding the second-largest river in Kyushu, and having outlying islands and a power plant in its city area — this town’s form stands upon the past of a centrality from antiquity that the geography of the Sendai River basin held.

What characterizes Satsumasendai is that, while it holds the past of the center of ancient Satsuma and a wide city area including outlying islands and a power plant, it is gently losing population and deepening its aging after the merger. From the 102,370 of 2005, when data can be taken, to the 92,403 of 2020, some ten thousand were lost over fifteen years. In this land of the northwest of Kagoshima Prefecture, distant from Kagoshima City, one can read that, within the current of the younger generation moving to the city, the decrease of population and the deepening of aging are advancing. In particular, one can read that, in district areas of outlying islands such as the Koshikijima Islands, are included districts where the decrease of population and the aging come out more strongly than in the central part on the mainland side.

On the other hand, the fiscal strength is kept in the middle rank. The Fiscal Capacity Index of 0.59 is a level able to cover about six-tenths of expenditure with its own tax revenue — the middle rank for a regional city. One can read that the siting of the Sendai Nuclear Power Plant and the like gives a thickness to the tax source, such as the fixed-asset tax. The Childcare Waitlist, too, was zero in both 2024 and 2025, and the receiving capacity against demand is kept. The center of ancient Satsuma is now, after the merger, gently losing population and deepening its aging while keeping its fiscal strength in the middle rank. A gently falling population, an aging passing three in ten, finances kept in the middle rank — these look like separate numbers, yet upon the same foundation of a wide city area holding a power plant and outlying islands in the basin of the second-largest river in Kyushu they entangle into one through the thickness of the fixed-asset tax. With a single number alone, the figure of the town of the Sendai River basin cannot be formed.

The roles Satsumasendai has held in this Sendai River basin can be counted in several. One is the past of the center of ancient Satsuma, where the ruins of the provincial seat and of a Kokubunji were found, holding the old layer of the pivot of the politics and culture of Satsuma. Another is the Sendai River, the second-largest river in Kyushu, and the Koshikijima Islands added to the city area by the 2004 merger, keeping the character of widely holding river and sea. And the Sendai Nuclear Power Plant at Kuminzaki gives this town the structure proper to it of a base of energy.

Satsumasendai is a town where an ancient center, a river, outlying islands and a power plant dwell together. From the land of the center of ancient Satsuma, to a wide city area holding a river and outlying islands, to a town where a power plant is sited — the geography of "opening onto the basin of the Sendai River, the second-largest river in Kyushu" set the centrality of antiquity, added the outlying islands through merger, drew in the power plant, and set the form of the town. On this land that opened onto the basin of the Sendai River, the second-largest river in Kyushu, the centrality of antiquity conveyed by the ruins of a Kokubunji, the Koshikijima Islands added by merger, and the power plant at Kuminzaki overlap as layers of different eras.