This town’s bay, on an intricate rias coast, deepens immediately from the shore. That deep bay became a natural good harbor into which large ships can enter, and an industrial port handling one of the largest cargo volumes in Shikoku. In the hills behind there are limestone mines, and from the port limestone and the material made by firing it are shipped out, making up much of the cargo. Sawmilling and processing sites line the back of the port too. A warm noodle dish made in an earthen pot is also known as this town’s specialty. This town, the land of the rias industrial port, did not join the Heisei mergers and walked on its own, and while doing so has lost population. Susaki’s numbers are the record of a town engraved by the deep bay and the shipping out of limestone.
A city that opens upon a land facing Tosa Bay in the central part of Kochi Prefecture. The population has fallen from 27,569 in 2000 to 20,590 in 2020. Because this city did not go through the Heisei mergers but walked on its own, its recent population trend has no merger-derived step. What I (Atlas) want to read here is not the sign "a city in the prefecture’s center," but the causal thread: how the history — the deep bay and the shipping out of limestone — is translated into today’s population and finances.
01 · Seeing the present Susaki in its numbers
In the latest Population Census the population is about twenty-one thousand (20,590 in 2020). Because this city did not go through the Heisei mergers but walked on its own, its recent population trend has no merger-derived step. From 27,569 in 2000, through 26,039 in 2005, 24,698 in 2010, 22,606 in 2015, to 20,590 in 2020, about seven thousand fell over twenty years.
Looking inside, the figure of a rias industrial-port town raising its age greatly appears. The share aged 65 and over passed four in ten at 40.6% in 2020. The household-with-children share was 14.5% (2020), and the crude birth rate was 4.2 per thousand (2020). The Childcare Waitlist was zero in both 2024 and 2025. The Fiscal Capacity Index was 0.41 in fiscal 2023, a level able to cover only about four-tenths of expenditure with its own tax revenue. The figure of the land of the rias industrial port, losing population on its own without a merger, appears in the numbers. Why it takes this shape cannot be read without going back over the history of the deep bay and the shipping out of limestone.
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 deep rias bay, Shikoku’s leading cargo industrial port, the shipping out of limestone and paper, the solitary course — the history behind the numbers
This town’s skeleton is set by the history of the deep rias bay, an industrial port handling one of the largest cargo volumes in Shikoku, the shipping out of limestone, paper and the like, and a solitary course. The starting layer is the deep bay. This town’s bay, on an intricate rias coast, deepens immediately from the shore. That deep bay became a natural good harbor into which large ships can enter. A bay that deepens immediately from the shore was this town’s foundation.
This deep bay became an industrial port. The bay was developed as an industrial port handling one of the largest cargo volumes in Shikoku, and the limestone carried from the limestone mines in the hills behind, and the material made by firing it, make up much of the cargo shipped out. Sawmilling and processing sites line the back of the port too. A warm noodle dish made in an earthen pot is also known as this town’s specialty. The road by which it became a city mirrors this town too. This town took city status in the middle of the Showa era by becoming one with the surrounding towns and villages, but did not join the Heisei mergers and walked on its own. The deep rias bay, Shikoku’s leading cargo industrial port, the shipping out of limestone and paper, and the solitary course — this town’s shape stands upon the deep-bay and limestone history engraved by a bay that deepens immediately from the shore.
Source: Susaki City / Susaki Port (along Tosa Bay in central Kochi; a natural good harbor on the ria coast of Susaki Bay, a major port and an industrial port with the largest cargo volume in Shikoku — overview) / Susaki City / limestone and cement (limestone and cement make up much of the port’s handled cargo, with limestone mines, cement plants and sawmilling in the hinterland; the local specialty, nabeyaki ramen — overview) / Susaki City (in central Kochi, about 30 km west of the prefectural capital; in 1954 Susaki Town + Tanogo Village + Uranouchi Village + Asou Village + Shinjo Village merged to take city status; it did not take part in the Heisei mergers and continued on its own — overview)
03 · In the land of the rias industrial port, losing population on its own
What characterizes Susaki is that, while holding the history of the deep bay and limestone, it loses population on its own without a merger. From 27,569 in 2000 to 20,590 in 2020, about seven thousand fell over twenty years. Even in this town, holding an industrial port handling one of the largest cargo volumes in Shikoku, one can read that a part of the young generation moved toward larger cities, and the age of the whole town has risen greatly. That the share aged 65 and over passed four in ten at 40.6% in 2020 is an expression of this.
On the other hand, the Childcare Waitlist was zero in both 2024 and 2025, the household-with-children share was 14.5% (2020), and the crude birth rate was 4.2 per thousand (2020). A Fiscal Capacity Index of 0.41 is a level able to cover only about four-tenths of expenditure with its own tax revenue. For a city of about twenty thousand, a fiscal capacity of 0.41 is by no means thick. That it can keep this level at this scale can be read as the port handling one of the largest cargo volumes in Shikoku and the limestone industry underpinning the foundation of tax revenue. The terrain of a bay that deepens immediately from the shore has given this small city a footing of industry.
Source: Population Census (Statistics Bureau, MIC) / Local Government Finance Survey, Fiscal Capacity Index (MIC) / Childcare Facility Status Report (Children and Families Agency)
04 · A bay that deepens immediately from the shore called in Shikoku’s leading cargo port
What decided Susaki’s industry was neither the city’s extent nor the number of people, but the terrain of the bay itself. One is the history of a deep bay where, on an intricate rias coast, the water deepens immediately from the shore, and large ships can enter. Another is the character of an industrial port where that deep bay handles one of the largest cargo volumes in Shikoku. And it has the face of a land of shipping out limestone, where the limestone carried from the limestone mines in the hills behind, and the material made by firing it, are shipped out. On an intricate rias coast, the water deepens immediately from the shore. For just that reason large ships can enter, and it became an industrial port handling Shikoku’s leading cargo.
While many ports secure depth with long breakwaters or dredging, Susaki’s natural terrain of a rias bay gave from the start the depth into which large ships can enter. The limestone carried from the hills behind is shipped out from that deep bay. What supports the industry of this town facing Tosa Bay was a condition that barely appears on a map — the water depth right at the shore.
Source: Susaki City / Susaki Port (along Tosa Bay in central Kochi; a natural good harbor on the ria coast of Susaki Bay, a major port and an industrial port with the largest cargo volume in Shikoku — overview) / Susaki City / limestone and cement (limestone and cement make up much of the port’s handled cargo, with limestone mines, cement plants and sawmilling in the hinterland; the local specialty, nabeyaki ramen — overview) / Susaki City (in central Kochi, about 30 km west of the prefectural capital; in 1954 Susaki Town + Tanogo Village + Uranouchi Village + Asou Village + Shinjo Village merged to take city status; it did not take part in the Heisei mergers and continued on its own — overview)
05 · Atlas’s note — the thinning of population, and the thickness of an industrial foundation
Lay out Susaki’s numbers and the indicators of an industrial-port town raising its age greatly line up: a population falling on its own, an aging rate of 40.6%, a household-with-children share of 14.5%, and a fiscal capacity of 0.41. But what I want to look at before the indicators is rather the relation in which the very terrain of the sea — water deepening immediately from the shore — links directly to the strength of an industrial port into which large ships can enter, the terrain directly regulating the industry. While many ports secure depth with long breakwaters or dredging, this town’s natural terrain of a rias bay gave a deep port from the start. The chain in which terrain became, just so, the foundation of industry explains this town’s numbers well.
The other thing I want to consider is that, while the population has thinned to a little over twenty thousand, the fiscal capacity, at 0.41, keeps a certain level for the scale of the population. The port handling Shikoku’s leading cargo and the limestone industry behind keep the foundation of tax revenue against the scale of the population. The thinning of population and the thickness of an industrial foundation do not necessarily face the same way — measure a town’s strength by population alone, and one misreads the image. The population thinned to a little over twenty thousand. Even so, a fiscal capacity of 0.41 keeps a certain level for the scale of the population, because the port handling Shikoku’s leading cargo and the limestone industry behind leave a tax base thick relative to the population. The thinning of population and the thickness of an industrial foundation do not necessarily face the same way. Measure a town’s strength by the number of those who live there alone, and this town’s numbers are misread.
Source: Population Census (Statistics Bureau, MIC) / Susaki City / Susaki Port (along Tosa Bay in central Kochi; a natural good harbor on the ria coast of Susaki Bay, a major port and an industrial port with the largest cargo volume in Shikoku — overview) / Susaki City / limestone and cement (limestone and cement make up much of the port’s handled cargo, with limestone mines, cement plants and sawmilling in the hinterland; the local specialty, nabeyaki ramen — overview) / Susaki City (in central Kochi, about 30 km west of the prefectural capital; in 1954 Susaki Town + Tanogo Village + Uranouchi Village + Asou Village + Shinjo Village merged to take city status; it did not take part in the Heisei mergers and continued on its own — 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_