One corner of this city has long been home to many smiths who forge swords, and the blades bearing that place-name became a group of treasured swords renowned throughout the nation. The skill of striking, tempering and polishing iron was handed down across the generations. Another corner of the same city is a hill facing the waters of the Seto Inland Sea, where an evergreen tree of silver leaves is grown, and where the pressing of oil from its fruit and the cultivation of oysters along the shore have continued. The swordsmiths’ village and the seaside hill — the iron craft of the mountain side and the harvest of the sea side dwell together within one city. This town, a land that bound a swordsmiths’ village to a seaside hill, was born in the Heisei era when three towns became one, and has gently lost population. Setouchi’s numbers are the record of a town etched by the history of sword-forging and the sea.
A city that opens onto a land facing the Seto Inland Sea in the southeastern part of Okayama Prefecture. After three towns became one in 2004 and the city was founded, the population fell gently, from 39,081 in 2005 to 36,048 in 2020. Because this city was founded by a new merger, its recent population is read on the post-founding city area. What I (Atlas) want to read here is not the sign "a city of the prefecture’s southeast," but the causal thread: how the history — sword-forging and the sea — is translated into today’s population and finances.
01 · Measuring the present Setouchi in its numbers
In the 2020 Population Census, Setouchi’s population is 36,048 — about thirty-six thousand. Because this city was newly founded in 2004 when three towns became one, the statistics are read on the post-founding city area. On that area it has fallen gently, from 39,081 in 2005, to 37,852 in 2010, to 36,975 in 2015, to 36,048 in 2020.
Looking inside, the figure of a seaside city raising its age gently appears. The share aged 65 and over was 34.5% in 2020, passing three in ten. The household-with-children share was 20.2% in 2020, somewhat high for the population size, and the crude birth rate was 5.0 per thousand in 2020. The Childcare Waitlist was zero in both 2024 and 2025. The Fiscal Capacity Index was 0.55 in fiscal 2023 — a middling level for a regional city, able to cover a little over half of expenditure with its own tax revenue. The figure of a land that bound a swordsmiths’ village to a seaside hill, gently losing population after becoming one with three towns, appears in the numbers. Why it takes this shape cannot be read without going back over the history of sword-forging and the sea.
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 · A swordsmiths’ village, the harvest of a seaside hill, the oyster sea, and the merger of three towns — the history behind the numbers
What set this town is the swordsmiths’ village, the harvest of the seaside hill, the sea where oysters are grown, and the merger of three towns. The first layer is the village of swords. One corner of this city has long been home to many smiths who forge swords, and the blades bearing that place-name became a group of treasured swords renowned throughout the nation. The skill of striking, tempering and polishing iron has been handed down across the generations. A village of smiths who forge swords lies on the mountain side of this town.
This other corner is a hill facing the waters of the Seto Inland Sea. An evergreen tree of silver leaves is grown, and the pressing of oil from its fruit continues. Along the shore the cultivation of oysters has been carried on. The iron craft of the mountain side and the harvest of the sea side stand side by side within one land. The road by which it became a city mirrors this town, too. In 2004 the village of swords, the seaside hill, and the land between them — three towns — became one and were newly founded. The city’s name is taken from the name of the inland sea it faces. The swordsmiths’ village, the harvest of the seaside hill, the oyster sea, and the merger of three towns. The iron craft of the mountain and the harvest of the sea — livelihoods that were, in origin, separate — are bound together under the name of one city. That is the figure of Setouchi.
Source: Setouchi City / Bizen-Osafune (the Osafune district of the former Osafune Town has long had many swordsmiths, famed nationwide as Bizen-Osafune, a land of swords — overview) / Setouchi City / Ushimado (the former Ushimado Town faces the Seto Inland Sea, a coastal land active in olive and oyster cultivation — the Ushimado Olive Garden — overview) / Setouchi City (southeastern Okayama; formed on 2004-11-01 by the new merger of three towns — Oku, Ushimado and Osafune of Oku District; statistics treat the post-2005 figures after its founding — overview)
03 · In a land that bound a swordsmiths’ village to a seaside hill, becoming one with three towns and gently losing population
What characterizes Setouchi is that, while bearing the history of sword-forging and the sea, it has gently lost population after becoming one with three towns. On the post-founding city area, about three thousand fell over fifteen years, from 39,081 in 2005 to 36,048 in 2020. The decline is gentle compared with inland mountain cities, and one can read that the mild seaside climate and the ease of commuting to a large nearby city have held back any sharp thinning of population. That the share aged 65 and over reached 34.5% in 2020, above three in ten, while the household-with-children share stood at 20.2%, somewhat high for the population size, is one expression of this.
Meanwhile the Childcare Waitlist was zero in both 2024 and 2025, and the crude birth rate was 5.0 per thousand in 2020. The Fiscal Capacity Index of 0.55 is a middling level for a regional city, able to cover a little over half of expenditure with its own tax revenue. The population fell by about three thousand after the founding, the aging passed three in ten, and the fiscal strength is middling for a regional city. Even among cities founded in the same Heisei merger, this city — which bound the swordsmiths’ village of the mountain to the harvest of the seaside — grows old at a pace not as quick as the inland mountains. The difference of siting gives rise to the difference of decline — that nuance does not appear from looking at the single line of population alone.
Source: Population Census (Statistics Bureau, MIC) / Local Government Finance Survey, Fiscal Capacity Index (MIC) / Childcare Facility Status Report (Children and Families Agency)
04 · The iron craft of the mountain and the harvest of the sea stood side by side within one city
Setouchi has, etched into a land facing the inland sea, several functions of its own. One is the history of a swordsmiths’ village, whose blades bearing the place-name are renowned nationwide. Another is the character of a seaside harvest, where on a hill facing the waters of the Seto Inland Sea oil is pressed from the fruit of a silver-leaved tree. And it holds the face of a seaside place to live, where oysters are grown along the shore and one can commute to a large nearby city. The iron craft of the mountain side and the harvest of the sea side stand side by side within one city.
It bound a swordsmiths’ village to a seaside hill — that history of merger set the iron craft of the mountain side beside the harvest of the sea side, under the name of one city. The mountain livelihood of striking iron and the sea livelihood of raising a harvest are, in origin, separate things. They dwell together within the same city area, while the seaside warmth and the convenience of commuting hold back any sharp thinning of population. In the southeastern part of Okayama Prefecture, in this city facing the inland sea, the separate livelihoods of the mountain swordsmiths and the seaside harvest still stand side by side under the name of one city.
Source: Setouchi City / Bizen-Osafune (the Osafune district of the former Osafune Town has long had many swordsmiths, famed nationwide as Bizen-Osafune, a land of swords — overview) / Setouchi City / Ushimado (the former Ushimado Town faces the Seto Inland Sea, a coastal land active in olive and oyster cultivation — the Ushimado Olive Garden — overview) / Setouchi City (southeastern Okayama; formed on 2004-11-01 by the new merger of three towns — Oku, Ushimado and Osafune of Oku District; statistics treat the post-2005 figures after its founding — overview)
05 · Atlas’s note — the difference of siting divides the decline after a merger
Lay out Setouchi’s numbers and the indicators of a seaside city raising its age gently line up: a gently falling population, an aging rate of 34.5%, a household-with-children share of 20.2%, and a fiscal capacity of 0.55. But when I (Atlas), with the eye of a certified public accountant reading ledgers, look at them, what I want to read here is the way two lands of differing character were layered: that this town "holds within one city both a swordsmiths’ village renowned nationwide and the harvest of a seaside hill," two lands of differing character joined into one city by merger. The skill of the mountain side that strikes iron and the work of the sea side that raises a harvest are, in origin, separate livelihoods. They are bound under the name of one city. When lands of differing character become one, the numbers of the whole city mirror the figure of neither land as it is — that chain explains this town’s numbers well.
The other thing I want to consider is that this town’s decline is "gentle compared with inland mountain cities." The mild seaside climate and the ease of commuting to a large nearby city are seen to hold back any sharp thinning of population. Here lies the key to reading the numbers of this city of Setouchi. Founded in the same Heisei merger and letting go of the same three-thousand scale, an inland mountain city and a city within a seaside commuting sphere take wholly different slopes thereafter. Even where the circumstances of founding are the same, whether one faces the sea or is ringed by mountains divides the speed of the path after merger. The gentleness of Setouchi’s decline may be said to be a speed decided not by history, but by the siting of facing the sea.
Source: Population Census (Statistics Bureau, MIC) / Setouchi City / Bizen-Osafune (the Osafune district of the former Osafune Town has long had many swordsmiths, famed nationwide as Bizen-Osafune, a land of swords — overview) / Setouchi City / Ushimado (the former Ushimado Town faces the Seto Inland Sea, a coastal land active in olive and oyster cultivation — the Ushimado Olive Garden — overview) / Setouchi City (southeastern Okayama; formed on 2004-11-01 by the new merger of three towns — Oku, Ushimado and Osafune of Oku District; statistics treat the post-2005 figures after its founding — 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 (wave-cs1 2026-06-05)) handled the shaping of the text. Evaluative or predictive language (such as “a good buy” or “attractive”) is intentionally left out. Revision id: wavecs1_