This is a town that became a railway hub by the political power of one person, and lost that seat to a single tunnel. In the mid-Meiji era, in laying the main line that joined Tokyo and Nagoya, one railway official, a native of this valley, had the line — which should by rights have crossed the pass — make a large detour south and pass through this town. That detour was called the "Daihachi loop," after his name. The town gained a main-line station and became a hub where people and goods gathered. But eighty years later, a long tunnel pierced beneath the pass, and the main line, which had detoured, was rejoined straight. The main-line station retreated into a branch-line station. Now this town is losing nearly four thousand of its population over twenty years. Tatsuno’s numbers are the record of a town inscribed with the history of a railway that came by political power and went by a tunnel.
A town in the southern part of Nagano Prefecture, opening onto the very northern edge of the Ina Valley, flanked by the Southern Alps and the Central Alps. This town has walked its history as a hub through which, in the mid-Meiji era, the main line passed in a large detour south by the power of a railway official native to this valley, and as a place that was, eighty years later, cut off from the main line by a tunnel and retreated into a branch-line station. The population has fallen by nearly four thousand over twenty years, from 22,407 in 2000, through 21,801 in 2005, 20,909 in 2010 and 19,770 in 2015, to 18,555 in 2020. What I (Atlas) want to read here is not the sign "the town of fireflies," but the causal thread: how the history — a railway that came by political power and went by a tunnel — is translated into today’s population.
01 · See the present Tatsuno-machi in its numbers
In the latest Population Census the population is about eighteen thousand five hundred (18,555 in 2020). From 22,407 in 2000, through 21,801 in 2005, 20,909 in 2010 and 19,770 in 2015, to 18,555 in 2020, it fell by nearly four thousand over twenty years. The fall is about seventeen percent, continuing as if descending a slope.
Looking inside the figures, the figure of a town at the northern edge of the Ina Valley, retreated from the main line, appears. The share aged 65 and over rose from 23.4% in 2000 to 37.7% in 2020 — about fourteen points over twenty years, drawing near four in ten. The household-with-children share is 19.8% in 2020. The employment rate is 55.4% in 2020. The Childcare Waitlist was zero in both 2024 and 2025. The Fiscal Capacity Index was 0.45 in fiscal 2023 — a level whose own tax revenue covers a little over four-tenths of expenditure. The figure of a town once a railway hub, losing population and raising the town’s age after retreating from the main line, appears in the numbers. Why it takes this shape cannot be read without going back over the history of a railway that came and went.
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 Daihachi loop, the eighty-year hub, the Shiojiri Tunnel — the history behind the numbers
A main line brought by political power. A seat as a hub spanning eighty years. And the exit by a single tunnel. The modern shape of Tatsuno-machi is settled by these three. The opening layer is the detour. In the mid-Meiji era, in laying the main line that reached from the direction of Tokyo to Nagoya, the line should by rights have been joined straight across the pass. But one railway official, a native of this Ina Valley, had that line changed to a route that, rather than the pass, went down in a large detour south to pass through this town. By that detour, called the "Daihachi loop" after his name, when the line opened at the end of the Meiji era, this town gained a main-line station and became a railway hub where people and goods gathered. A main-line station brought by political power — that is this town’s modern foundation.
That seat as a hub lasted about eighty years. But a turning point came. A long tunnel was dug beneath the pass, and the main line, which had detoured, was rejoined straight. The journey via this town, which had until then required twenty-eight kilometers, shrank to about twelve kilometers through the tunnel — to less than half. The main line, gaining speed and nearness, no longer needed to loop around this town. The line that had passed through this town retreated from a main line to a branch line that connects to a dead end. The hub station became a branch-line station. A main line that came by political power goes by the power of technology — the detour of the Daihachi loop, the eighty-year hub, and the tunnel of Shiojiri. A railway that came by political power and went by a tunnel — upon that modern history this town’s present stands.
03 · At the northern edge of the valley, retreated from the main line, the population falls
What characterizes Tatsuno-machi is that, while holding the history of having once been a railway hub, it has, after retreating from the main line, lost nearly four thousand of its population over twenty years. From 22,407 in 2000 to 18,555 in 2020, the fall is about seventeen percent. The modern standing as a railway hub gathered people and goods to this town and made it flourish. But that its main line retreated to a branch line worked, as it can be read, toward setting this town somewhat aside from the axis of the flow of people and goods. The position at the very northern edge of the Ina Valley is apart from the places to work and to learn of the larger cities, and after losing the thick axis of the main line, it finds it hard to hold the younger generation. That the share aged 65 and over drew near four in ten at 37.7% in 2020, rising fourteen points over twenty years, is an expression of that flow.
On the other hand, the Fiscal Capacity Index was 0.45 in fiscal 2023 — a level whose own tax revenue covers a little over four-tenths of expenditure. This can be read as an expression of how this town, once flourishing on silk reeling, now holds the trades of precision, including factories that make microscopes and medical instruments, and supports the tax source to some degree. The Childcare Waitlist was zero in both 2024 and 2025, and the household-with-children share is 19.8% in 2020. The employment rate is 55.4% in 2020. A population fall of about seventeen percent, an aging drawing near four in ten, and yet a fiscal capacity of a little over four-tenths. These are separate numbers, yet all stem from the same history: that "in the northern edge of a valley that lost the thick axis of the main line, the hands of manufacturing remained." Read by pulling out a single number alone, and you mistake the image.
Source: Population Census (Statistics Bureau, MIC) / Local Government Finance Survey, Fiscal Capacity Index (MIC) / Childcare Facility Status Report (Children and Families Agency)
04 · At the northern edge of a valley where a railway came and went, a firefly gorge remained
Tatsuno holds several histories of its own. One is the modern starting point of having become a railway hub when the main line passed in a large detour south by the political power of a railway official native to this valley. Another is the character that, eighty years later, the main line was rejoined straight by a tunnel beneath the pass, and it retreated from a main-line station to a branch-line station. And beside that railway tale lies one more history, of an utterly different cast. This town has a firefly gorge said to be the foremost in eastern Japan. By the silk-reeling labor once flourishing in the neighboring district, silkworms and the like flowed from the lake into the Tenryu River, increasing the food of the small snails fireflies feed on, and the fireflies increased naturally, it is told. At the end of the Meiji era one teacher called for their protection, and in time the fireflies of this gorge became a prefectural natural monument.
Tatsuno is a town where, at the northern edge of a valley a railway came and went, a firefly gorge remained. From the detour of the Daihachi loop, through the eighty-year hub and the tunnel of Shiojiri, to the population fall — the geography of "the northern edge of the Ina Valley, flanked by the Southern Alps and the Central Alps" gave this town two histories of differing nature: the railway tale that avoids the pass and threads the valley, and the firefly gorge that the silk reeling of the neighboring district raised along the river. Both that called the main line to the town and that the main line departed were decisions made outside the town. What remained is the light of the early-summer gorge, raised by the remnant of silk reeling carried along the river.
Source: Tatsuno Town / the Chuo Main Line "Daihachi loop" (the Chuo Main Line was planned as a line connecting Hachioji of the Kobu Railway with Nagoya via Shiojiri; at the invitation in 1894, the railway official Daihachi Ito, a native of the Ina Valley, had the route changed to make a large detour south through Tatsuno rather than over the Shiojiri Pass; the route looping through Tatsuno was therefore called the "Daihachi loop" after Daihachi Ito; in 1906 the Okaya-Tatsuno-Shiojiri section opened and Tatsuno became a railway hub, but in 1983 the opening of the Shiojiri Tunnel directly connected Okaya and Shiojiri (the about 28 km via Tatsuno shortened to about 12 km), and the line through Tatsuno fell from a main line to a branch line (the Tatsuno branch) — overview) / Tatsuno Town / the fireflies of Matsuo Gorge and silk reeling (Matsuo Gorge is said to be the foremost firefly spot in eastern Japan and is a prefectural natural monument; the silk-reeling industry once flourishing in the Suwa region let silkworms and the like flow from Lake Suwa into the Tenryu River, increasing the food of the kawanina snails that fireflies feed on, so that fireflies increased naturally; in 1912 the teacher Teruhiko Kobayashi distributed "The Tale of the Fireflies" to call for their protection, and in 1925 they were designated a prefectural natural monument; in 1947 Inatomi Village took town status and was renamed Tatsuno Town — overview) / Population Census (Statistics Bureau, MIC)
05 · Atlas note — the railway came from outside and left for outside; only the hands of precision remained in the valley
Lay out Tatsuno’s numbers and the indicators of a town at the northern edge of the Ina Valley, retreated from the main line, line up: a population fall of nearly four thousand over twenty years, an aging rate of 37.7%, a household-with-children share of 19.8%, an employment rate of 55.4%, and a fiscal capacity of 0.45. But when I (Atlas) trace this town’s history with the accountant’s eye, what I first stop at is the point that this town’s flourishing and its decline were both brought about by "decisions made outside the town." That the main line passed through this town was owed not to the town’s own power but to the political power of one official who happened to be a native of this valley. And that the main line departed, too, was owed not to a fault of the town but to a decision of a wider region — to dig a tunnel beneath the pass. The town was, apart from its own will, made a hub, and then unmade as a hub.
One more thing to weigh is what this town has held by its own hand, amid that "fate decided outside." In my view, the answer lies behind the number of a fiscal capacity of 0.45, held despite a population that keeps falling. This town, once flourishing on silk reeling, has, even after losing the main line, rooted in this valley the trades of precision that make microscopes and medical instruments. The thick axis of the railway came from outside and left for outside, but the hands of manufacturing remained within the town. Buffeted by a fate decided outside, yet the trades made by its own hands hold the stamina of finances at a little over four-tenths — read this way, this town’s numbers come to look not as a mere record of decline, but as a record of the contest between outside decisions and home trades. Whether you read it past as the sign "the town of fireflies," or see it as "a town where, at the northern edge of a valley a railway came and went, a firefly gorge remained," changes with how the reader lives. On an early-summer evening, the countless lights that fill the Matsuo Gorge are, it is told, the remnant of what the age of silk reeling let flow into the river. Even after the railway that made the town flourish and decline drew away, that faint light alone still flickers in the gorge.
Source: Population Census (Statistics Bureau, MIC) / Tatsuno Town / the Chuo Main Line "Daihachi loop" (the Chuo Main Line was planned as a line connecting Hachioji of the Kobu Railway with Nagoya via Shiojiri; at the invitation in 1894, the railway official Daihachi Ito, a native of the Ina Valley, had the route changed to make a large detour south through Tatsuno rather than over the Shiojiri Pass; the route looping through Tatsuno was therefore called the "Daihachi loop" after Daihachi Ito; in 1906 the Okaya-Tatsuno-Shiojiri section opened and Tatsuno became a railway hub, but in 1983 the opening of the Shiojiri Tunnel directly connected Okaya and Shiojiri (the about 28 km via Tatsuno shortened to about 12 km), and the line through Tatsuno fell from a main line to a branch line (the Tatsuno branch) — overview) / Tatsuno Town / the fireflies of Matsuo Gorge and silk reeling (Matsuo Gorge is said to be the foremost firefly spot in eastern Japan and is a prefectural natural monument; the silk-reeling industry once flourishing in the Suwa region let silkworms and the like flow from Lake Suwa into the Tenryu River, increasing the food of the kawanina snails that fireflies feed on, so that fireflies increased naturally; in 1912 the teacher Teruhiko Kobayashi distributed "The Tale of the Fireflies" to call for their protection, and in 1925 they were designated a prefectural natural monument; in 1947 Inatomi Village took town status and was renamed Tatsuno Town — 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 (Daiki 2026-06-02)) handled the shaping of the text. Evaluative or predictive language (such as “a good buy” or “attractive”) is intentionally left out. Revision id: wave29w_