This land is at the north end of a peninsula ringed on three sides by sea. Its intricate coast has held many fine harbors. In the Edo age, ships chasing whales went out from those harbors, and it flourished as a whaling base. In the Meiji age, coal was dug from the earth, and the harbors bustled with coal. When the age of coal departed, a factory building great ships was put up in this land, and the livelihood bound to the sea shifted from whales to coal, and then to shipbuilding. Five towns were bound into one, and the present city was established. This peninsular land ringed on three sides by sea, having bound five towns into a city, has lost population after the merger. Saikai’s numbers are the record of a town in which whaling, coal and shipbuilding are inscribed.
A city that opens in the west of Nagasaki Prefecture, in the north of the Nishisonogi Peninsula, on land ringed on three sides by sea. Because this city was established in 2005 by binding five towns anew into one, its population statistics as a city cover the period from 2005, after the establishment, on. From the 33,680 of 2005 to the 26,275 of 2020, it has decreased. What I (Atlas) want to read here is not the sign "a peninsular city," but the causal thread: how the history of whaling, coal and shipbuilding is translated into today’s population and finances.
01 · Seeing the present Saikai in its numbers
In the latest Population Census the population is about 26,000 (26,275 in 2020). Because this city was established in 2005 by binding five towns anew into one, its population statistics as a city cover the period from 2005, after the establishment, on. From the 33,680 of 2005, through the 31,176 of 2010, the 28,691 of 2015, to the 26,275 of 2020, some seven thousand have been lost over fifteen years.
Looking inside, the figure of a peninsular city ringed by sea raising its age appears. The share aged 65 and over rose from 34.2% in 2015 to 38.8% in 2020, nearing four in ten. The household-with-children share is 15.6% in 2020, and the crude birth rate is 6.1 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, with a large degree of reliance on the local allocation tax. The peninsula that drew in whales, coal and ships in turn loses population and advances its aging after the merger. Why it takes this form cannot be read without going back to the past of the peninsula’s harbors and whaling and coal and shipbuilding.
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 peninsula ringed on three sides by sea, the whaling base, the coal harbor, shipbuilding and a merger of five towns — the history behind the numbers
What supports Saikai’s past is the landform of a peninsula ringed on three sides by sea, the whaling base, the coal harbor, and shipbuilding and the merger of five towns. The oldest layer is the peninsula ringed by sea. This land lies in the north of the Nishisonogi Peninsula and is ringed on three sides by sea. Its intricate coast has held many fine harbors. The landform of a peninsula ringed on three sides by sea is this town’s foundation.
These fine harbors drew in, one after another, the livelihoods bound to the sea. In the Edo age, ships chasing whales went out from the harbors, and it flourished as a whaling base. In the Meiji age, coal was dug from the earth, and the harbors bustled with coal. When the age of coal departed, a factory building great ships was put up in this land. The livelihood bound to the sea shifted from whales to coal, and then to shipbuilding. The newest layer is the path to becoming a city. In 2005 the five towns of the peninsula were bound anew into one, and the present city was established. The peninsula ringed by sea, the whaling base, the coal harbor, shipbuilding and the merger of five towns — the land that piled these four layers is the present Saikai.
Source: Saikai City / the Nishisonogi Peninsula (located in the north of the Nishisonogi Peninsula of Nagasaki Prefecture, surrounded on three sides by the Goto Sea, Sasebo Bay and Omura Bay, almost entirely a ria coast — overview) / Saikai City / whaling, coal and shipbuilding (the ports along the Goto Sea thrived as whaling bases from the Edo period, bustled with coal mining from the Meiji era on, and a shipyard was established in 1973 — overview) / Saikai City (established on 2005-4-1 by the equal merger of the five towns of Saigi, Saikai, Oshima, Sakito and Oseto of Nishisonogi County; statistics cover the period after establishment — overview)
03 · In a peninsular land ringed on three sides by sea, losing population after the merger
What characterizes Saikai is that, while it holds the past of the shifting of the livelihoods of the sea, it is losing population after the merger. From the 33,680 of 2005, when the city was established, to the 26,275 of 2020, some seven thousand were lost over fifteen years. Even on this peninsula that shifted its livelihoods of the sea from whaling to coal to shipbuilding, one can read that much of the younger generation moved toward the larger cities and the town’s age as a whole rose. That the share aged 65 and over neared four in ten at 38.8% in 2020 is an expression of that.
On the other hand, the Childcare Waitlist was zero in both 2024 and 2025, the household-with-children share is 15.6% in 2020, and the crude birth rate is 6.1 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, showing the large degree of reliance on the local allocation tax seen in common across peninsular lands ringed on three sides by sea. The population fell by some seven thousand over fifteen years, the aging neared four in ten, and the body of the finances is thin on tax revenue alone. What overlap of numbers the peninsula that changed its livelihood three times has now settled into — that comes into view only when population, age and finances are laid out on a single sheet.
Source: Population Census (Statistics Bureau, MIC) / Local Government Finance Survey, Fiscal Capacity Index (MIC) / Childcare Facility Status Report (Children and Families Agency)
04 · A peninsula ringed on three sides by sea shifted its livelihoods of the sea one after another
The functions Saikai holds are not one. It has the face of a peninsula ringed by sea, lying in the north of the Nishisonogi Peninsula, ringed on three sides by sea, with an intricate coast holding many fine harbors. It also has the face of the shifting of the livelihoods of the sea, having shifted the livelihood bound to the sea one after another, from a whaling base of the Edo age, to a coal harbor of the Meiji era, and then to the shipbuilding of building great ships. And it holds the face of a land of merger, where the five towns of the peninsula were bound into one. The fine harbors of a peninsula ringed on three sides by sea drew in whaling, coal and shipbuilding to this land.
A peninsula ringed on three sides by sea shifted its livelihoods of the sea one after another — that is the town Saikai is. From the landform of a peninsula ringed by sea, to the whaling base, the coal harbor, and shipbuilding and the merger of five towns, what set the skeleton was the geography of "the fine harbors of a peninsula ringed on three sides by sea." Though the position has not moved for four hundred years, the livelihood the harbors call kept changing — from whales to coal to ships. The unchanging landform has supported an ever-changing industry.
Source: Saikai City / the Nishisonogi Peninsula (located in the north of the Nishisonogi Peninsula of Nagasaki Prefecture, surrounded on three sides by the Goto Sea, Sasebo Bay and Omura Bay, almost entirely a ria coast — overview) / Saikai City / whaling, coal and shipbuilding (the ports along the Goto Sea thrived as whaling bases from the Edo period, bustled with coal mining from the Meiji era on, and a shipyard was established in 1973 — overview) / Saikai City (established on 2005-4-1 by the equal merger of the five towns of Saigi, Saikai, Oshima, Sakito and Oseto of Nishisonogi County; statistics cover the period after establishment — overview)
05 · Atlas’s note — in a peninsular land ringed on three sides by sea, the strength of position and the limit of dwelling coexist
Lay out Saikai’s numbers and the indicators of a peninsular city ringed by sea line up: a population falling after the merger, an aging rate of 38.8%, a household-with-children share of 15.6%, and a fiscal capacity of 0.29. But when I (Atlas), as a certified public accountant, read these, what I want to read here is the shifting of industry — that this town "shifted the livelihood bound to the sea one after another, from whaling to coal, and then to shipbuilding." Chasing whales, digging coal, building ships — each is a livelihood drawn in by the same position of a peninsula ringed on three sides by sea, holding fine harbors. The chain by which, even with position constant, the industry drawn in shifted according to the age explains this town’s past well.
Another thing I want to consider is that this land, having shifted the livelihoods bound to the sea one after another, still keeps losing population. Whaling, coal and shipbuilding were each the sea’s industry of their age, but none reached the point of halting the outflow of population. The strength of a position open to the sea, and the limit, as a place to dwell, of a peninsula, coexist in this town.
Though it kept changing its livelihood from whales to coal to ships, the outflow of population does not halt — the strength of a position open to the sea did not necessarily connect to keeping the number of people who dwell. Whether to view this land as a peninsula where the sea’s livelihoods of whaling and shipbuilding continued, or as a land ringed on three sides by sea that still finds it hard to keep people, changes with where in living one turns one’s eyes. Though it kept changing its livelihood from whales to coal to ships, the outflow of population does not halt — the strength of being open to the sea did not connect to keeping the number of people who dwell.
Source: Population Census (Statistics Bureau, MIC) / Saikai City / the Nishisonogi Peninsula (located in the north of the Nishisonogi Peninsula of Nagasaki Prefecture, surrounded on three sides by the Goto Sea, Sasebo Bay and Omura Bay, almost entirely a ria coast — overview) / Saikai City / whaling, coal and shipbuilding (the ports along the Goto Sea thrived as whaling bases from the Edo period, bustled with coal mining from the Meiji era on, and a shipyard was established in 1973 — overview) / Saikai City (established on 2005-4-1 by the equal merger of the five towns of Saigi, Saikai, Oshima, Sakito and Oseto of Nishisonogi County; statistics cover the period after establishment — 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 (wave34-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: wave34w_