Across the sea to the west of this town rises an active volcano. That volcano, lying opposite across the bay, became joined by land to the peninsula across the way in a great eruption a little over a hundred years ago. What long linked the town and the prefectural capital was a ship crossing the bay. Because the land road takes a roundabout course, a ship cutting across the bay has linked life and the prefectural capital by the shortest route. This land, where the blessings and threat of a volcano are inscribed in the landform, has laid its life along a long, narrow city area on the bayshore. This land, the land opposite a volcano, has, ever since it became a city in the middle of the Showa era, never once undergone a merger; walking an independent path, it has lost population greatly. Tarumizu’s numbers are the record of a town in which a ship crossing the bay and an independent path are inscribed.
A city that opens onto a land in the northwest of the Osumi Peninsula of Kagoshima Prefecture, facing Kinko Bay to the west and lying opposite a volcano across the bay. The population has decreased greatly, from 20,107 in 2000 to 13,819 in 2020. Because this city, ever since it attained city status in the middle of the Showa era, has never once undergone a merger and walked an independent path, there is no merger-derived step in its recent population movement. What I (Atlas) want to read here is not the sign "a city of the peninsula’s northwest," but the causal thread: how the past of a ship crossing the bay and an independent path is translated into today’s population and finances.
01 · Seeing the present Tarumizu in its numbers
In the 2020 Population Census the population has shrunk to 13,819 — about fourteen thousand. Because this city, ever since it attained city status in the middle of the Showa era, has never once undergone a merger and walked an independent path, there is no merger-derived step in its recent population movement. From the 20,107 of 2000 it has decreased by some six thousand over twenty years, to 18,928 in 2005, 17,248 in 2010, 15,520 in 2015, and 13,819 in 2020.
Looking inside, the figure of a bayshore city raising its age greatly appears. The share aged 65 and over rose from 30.9% in 2000 to 38.5% in 2015 and 42.7% in 2020, passing well beyond four in ten. The household-with-children share is low, at 12.2% in 2020, and the crude birth rate is 4.7 per thousand in 2020. The Childcare Waitlist was zero in both 2024 and 2025. The Fiscal Capacity Index was 0.29 in fiscal 2023 — a level able to cover only a little under three-tenths of expenditure with its own tax revenue. The figure shows in the numbers: the land opposite a volcano, losing population greatly while remaining independent without a merger. Why it takes this form cannot be read without going back to the past of the position opposite a volcano, the ship crossing the bay, and the independent path.
Source: Population Census (Statistics Bureau, MIC) / Local Government Finance Survey, Fiscal Capacity Index (MIC) / Childcare Facility Status Report (Children and Families Agency) / Real Estate Information Library (MLIT)
02 · The land opposite a volcano, the ship crossing the bay, the long, narrow bayshore city area, the independent path — the history behind the numbers
What supports this town’s frame is the position opposite a volcano, the ship crossing the bay, the long, narrow bayshore city area, and the independent path. The starting layer is the land opposite a volcano. This land lies in the northwest of the Osumi Peninsula, faces Kinko Bay to the west, and lies opposite an active volcano across the bay. That volcano became joined by land to the peninsula in a great eruption a little over a hundred years ago. The position opposite a volcano was the foundation of this town.
This position called for a ship crossing the bay. Because to link the prefectural capital and the town by the land road takes a roundabout course, a ship cutting across the bay has linked life and the prefectural capital by the shortest route. On the bayshore, where the blessings and threat of a volcano are inscribed in the landform, the town has laid its city area long and narrow. The path to becoming a city, too, mirrors this town. This town, ever since it attained city status in the middle of the Showa era, has never once undergone a merger. The land opposite a volcano, the ship crossing the bay, the long, narrow bayshore city area, and the independent path — this town’s form stands upon the past of the bay’s ship and independence that the shore facing the volcano across the bay inscribed.
Source: Tarumizu City / Kinko Bay and Sakurajima (in the northwest of the Osumi Peninsula, facing Kinko Bay to the west; across the bay it lies opposite the volcano Sakurajima, and it is linked to the prefectural capital by ferry; in the great eruption of Sakurajima in 1914, Sakurajima became joined by land to the Osumi Peninsula — overview) / Tarumizu City / Sakurajima-Kinkowan Geopark (a land facing the active volcano Sakurajima and Kinko Bay, which was formed by volcanic activity, where life along the bay and the blessings and threats of the volcano are inscribed in the landform — overview) / Tarumizu City (on 1958-10-1 Tarumizu Town attained city status; thereafter it did not take part in the Heisei mergers and continued independently — overview)
03 · In the land opposite a volcano, losing population greatly while remaining independent
What characterizes Tarumizu is that, while it holds the past of being linked to the prefectural capital by a ship crossing the bay, it is losing population greatly, independent and without a merger. From the 20,107 of 2000 to the 13,819 of 2020, some six thousand were lost over twenty years. Even in this land linked to the prefectural capital by a ship crossing the bay, much of the younger generation moved to the larger city across the bay, and one can read that the town’s age as a whole rose greatly. That the share aged 65 and over passed well beyond four in ten at 42.7% in 2020, and the household-with-children share is low at 12.2%, is an expression of that.
On the other hand, the Childcare Waitlist was zero in both 2024 and 2025, and the crude birth rate is 4.7 per thousand in 2020. The Fiscal Capacity Index of 0.29 is a level able to cover only a little under three-tenths of expenditure with its own tax revenue. The land opposite a volcano is now losing population greatly and deepening its aging while remaining independent without a merger. A population decrease of some six thousand over twenty years, an aging passing well beyond four in ten, a low household-with-children share, finances thin on tax revenue alone — these, while separate numbers, upon the same site of a shore linked to the prefectural capital across the sea by a ship crossing the bay, entangle with one another through the outflow of the younger generation to the far shore. With a single number alone, the figure of the bayshore city cannot be drawn.
Source: Population Census (Statistics Bureau, MIC) / Local Government Finance Survey, Fiscal Capacity Index (MIC) / Childcare Facility Status Report (Children and Families Agency)
04 · A land where a shore facing a volcano across the bay was linked to the prefectural capital by a ship
The roles Tarumizu has held on this bayshore can be counted in several. One is that it holds the past of the land opposite a volcano — in the northwest of the Osumi Peninsula, facing Kinko Bay to the west, lying opposite an active volcano across the bay. Another is that it bears the character of a ship crossing the bay — because the land road takes a roundabout course, a ship cutting across the bay has linked life and the prefectural capital by the shortest route. And it holds the face of a bayshore land — laying its city area long and narrow along a bayshore where the blessings and threat of a volcano are inscribed. The position opposite a volcano has gathered here both the ship crossing the bay and the long, narrow bayshore life.
Tarumizu is a town in which a shore facing a volcano across the bay was linked to the prefectural capital by a ship. From the position opposite a volcano, to the ship crossing the bay, the long, narrow bayshore city area, and the independent path — the geography of "a shore facing the volcano across Kinko Bay" called for the ship crossing the bay, held the long, narrow bayshore life, and set the form of the town. On this shore in the northwest of the Osumi Peninsula of Kagoshima Prefecture, facing the active volcano across Kinko Bay, the ship crossing the bay and the life laid long and narrow along the bayshore overlap into one.
Source: Tarumizu City / Kinko Bay and Sakurajima (in the northwest of the Osumi Peninsula, facing Kinko Bay to the west; across the bay it lies opposite the volcano Sakurajima, and it is linked to the prefectural capital by ferry; in the great eruption of Sakurajima in 1914, Sakurajima became joined by land to the Osumi Peninsula — overview) / Tarumizu City / Sakurajima-Kinkowan Geopark (a land facing the active volcano Sakurajima and Kinko Bay, which was formed by volcanic activity, where life along the bay and the blessings and threats of the volcano are inscribed in the landform — overview) / Tarumizu City (on 1958-10-1 Tarumizu Town attained city status; thereafter it did not take part in the Heisei mergers and continued independently — overview)
05 · Atlas’s note — nearness carries the daily convenience and the outflow of people on the same single sea route
Lay out Tarumizu’s numbers and the indicators of a bayshore city deepening its age line up: a population falling greatly while independent, an aging rate of 42.7%, a household-with-children share of 12.2%, and a fiscal capacity of 0.29. As one (Atlas) whose eye goes to how nearness and farness tell on the balance of accounts, what I want to follow here is the past of nearness across the sea — that this town "has relied for its bond with the prefectural capital not on the land road but on a ship crossing the bay." Across the sea it lies opposite the prefectural capital and looks near, but by the land road it takes a roundabout course around the peninsula. The ship crossing the bay has filled that distance by the shortest route. The site, where nearness and farness reverse between sea and land, explains the form of this town’s life well.
Another thing I want to consider is the largeness of the population decrease — some six thousand over twenty years. That the household-with-children share is low at 12.2% and the aging rate passes well beyond four in ten at 42.7% mirrors the structure in which the younger generation moved to the far side of the bay and are hard to return. The prefectural capital, near across the sea, while supporting life, also draws in the younger generation. Nearness carries both the advantage and the outflow — this view cannot be grasped while staring at a single number alone. Whether to read it off as the sign "a city of the peninsula’s northwest," or to see it as "a town in which a shore facing a volcano across the bay was linked to the prefectural capital by a ship," changes with the reader’s way of living. Across the sea it lies opposite the prefectural capital and is near; by the land road it takes a roundabout course around the peninsula. While the ship crossing the bay filled that distance by the shortest route, the same nearness carried the younger generation to the far shore and made it let go of some six thousand over twenty years. I leave the measuring of this nearness against one’s own commute, budget and family form to the very person who would live here, and I (Atlas) press no seal. Nearness carries the daily convenience and the outflow of people on the same single sea route.
Source: Population Census (Statistics Bureau, MIC) / Tarumizu City / Kinko Bay and Sakurajima (in the northwest of the Osumi Peninsula, facing Kinko Bay to the west; across the bay it lies opposite the volcano Sakurajima, and it is linked to the prefectural capital by ferry; in the great eruption of Sakurajima in 1914, Sakurajima became joined by land to the Osumi Peninsula — overview) / Tarumizu City / Sakurajima-Kinkowan Geopark (a land facing the active volcano Sakurajima and Kinko Bay, which was formed by volcanic activity, where life along the bay and the blessings and threats of the volcano are inscribed in the landform — overview) / Tarumizu City (on 1958-10-1 Tarumizu Town attained city status; thereafter it did not take part in the Heisei mergers and continued independently — overview)
Editor’s note: all figures and sources are drawn from official statistics. The prose follows Atlas’s voice, and AI (atlas-handcrafted-reverse-v1 (wave35-west 2026-06-04)) handled the shaping of the text. Evaluative or predictive language (such as “a good buy” or “attractive”) is intentionally left out. Revision id: wave35w_