Saga-shi

In the latest Population Census the population is about 233,000 (233,301 in 2020). Over the five years from the 236,372 of 2015, it fell by some three thousand. As the prefectural capital of Saga Prefecture, it has entered a phase of decline, but the manner of that decline is on the gentler side among the prefectural capitals of the same regions.

What I want to look at here is that the household-with-children share is high for a regional prefectural capital. The household-with-children share is 21.0% (2020), above the 18.2% of Matsuyama (38201) and the 18.0% of Kochi (39201). Those under fifteen fell by some two thousand, from 32,324 (2015) to 30,064 (2020), and the share aged 65 and over rose from 25.7% to 27.8%, but the thickness of households with children is relatively kept. The land price of residential land is around 48,000 yen per m², a low level for a prefectural capital. The Fiscal Capacity Index is 0.63 — a structure in which its own tax revenue cannot cover the standard expenditure on its own and the shortfall is made up by the local allocation tax, a form widely shared by prefectural capitals away from the major metropolitan spheres. The Childcare Waitlist was 0 in 2025. Why these numbers take this form cannot be read without going back to the past of a castle town and a plain.

Saga’s urban area lies on low, level ground that mastered water and was opened together with water. Originally in this land stood the "Muranaka Castle" of the Ryuzoji family, which the Nabeshima family rebuilt in the Keicho era into Saga Castle. Saga Castle was also called the "sinking castle," because it held a great body of water all around to submerge all but the keep and so block the enemy’s advance. The castle itself takes into its defense the geography of water-rich low ground.

In 1608 (Keicho 13) Nabeshima Naoshige, who had been a chief retainer of the Ryuzoji, took the seat of domain lord, and thereafter this land developed its commerce and industry as the castle town of the Nabeshima family’s Saga domain — Hizen. And at the close of the shogunate, because the tenth domain lord, Nabeshima Naomasa, pressed forward with domain reform, the Saga domain took part, together with Satsuma, Choshu and Tosa, in building the institutions of the new Meiji government. Upon what economic geography calls the path dependence centered on a castle town, the distinctive history of late-shogunate domain reform is layered.

The foundation that makes this castle town possible is the low, level ground of the Saga plain. The Saga plain, through which the Kase River — rising in the Sefuri mountains and pouring into the Ariake Sea — runs, has been opened by a mesh of waterways called "creeks" and by reclamation along the Ariake coast. The castle that used water for defense, and the commerce and industry that developed in its castle town, originally stand upon this low ground that river and sea and reclamation created.

What characterizes Saga is that, while the total population falls by some three thousand over five years, the household-with-children share is kept high for a regional prefectural capital. The household-with-children share of 21.0% is above that of Matsuyama and Kochi, prefectural capitals of the same regions. Those under fifteen fell by some two thousand, and the share of the elderly rose into the late twenties percent, but even amid the shrinking, the thickness of young households relatively remains.

One expression of that is the figure of the Childcare Waitlist being 0 in 2025. But the context of this differs from a major city pushing demand-surge over with supply to make it zero. It can be read as a 0 in a state where, as the absolute number of children gently falls, supply catches up with demand and the two are nearly balanced. Even the same "waitlist 0" changes its meaning entirely depending on whether, behind it, children are increasing or decreasing — in Saga’s case, with children gently falling, it settles at 0 around where the thickness of households with children and the supply of childcare are in balance. Children fall, aging advances, yet the household-with-children share is kept and the waitlist is 0 — only by layering those several flows does this town’s present come into view. This number, too, will be misread if not read together with its background.

In Saga, several faces of different origin live together. One is the castle town centered on the "sinking castle" — Saga Castle, which holds water to defend — an urban area that developed commerce and industry as the seat of the Nabeshima’s Saga domain and, at the close of the shogunate, was one of the four of Satsuma, Choshu, Tosa and Hizen. Another is the Saga plain, through which the Kase River runs from the Sefuri mountains to the Ariake Sea, where a vast low, level ground opened by a creek-waterway network and reclamation spreads across the city area.

That plain gained a new face in modern times too. The riverbed of the Kase River, blessed with steady airflow and a wide space for takeoff and landing, gathers hot-air balloons from around the world in autumn as the venue of one of Asia’s largest international balloon meets — the Balloon Festa. Saga is the prefectural capital of Saga Prefecture, and from a castle town, to a land of the plain’s farming and waterways, to a riverbed where hot-air balloons gather — a single geography, "the low, level ground that river and sea and reclamation made," has swapped a different function onto itself in each age. The castle, the castle town, the plain’s agriculture and the balloon meet all rest, in origin, upon the same low, level ground.