Nakatsu-shi

In the latest Population Census the population is about 83,000 (82,863 in 2020). What I want to note first here is that the sudden increase of over seventeen thousand, from the 67,083 of 2000 to the 84,368 of 2005, is not the result of people increasing naturally. It is due to the incorporation of four neighboring towns and villages in 2005, and the step in the numbers mirrors that merger.

With that in mind, looking at the inside after the merger, from the 84,368 of 2005 to the 82,863 of 2020 it fell by only some one thousand five hundred over fifteen years, keeping nearly flat. This is rare among regional cities, many of which keep losing population, and one can read that the location of automobile-related factories and the like has held back the outflow of population. On the other hand, those under fifteen fell gently from the 12,359 of 2005 to the 10,962 of 2020, and the share aged 65 and over rose from 19.3% in 2000 to 30.0% in 2020, reaching three in ten. The household-with-children share is 19.0% in 2020, the Childcare Waitlist has been zero in recent years, and the Fiscal Capacity Index was 0.51 in fiscal 2023. The figure of a regional city keeping its population while, inside, the generations turn over, shows in the numbers. Why it takes this form cannot be read without going back to the past of the castle town.

Nakatsu’s skeleton is set by the castle layout one strategist drew. In 1588 Kuroda Kanbei (Yoshitaka), known as the strategist of Toyotomi Hideyoshi, began the construction of Nakatsu Castle at the mouth of the Yamakuni River. It is a waterside castle touching sea and river, and the ground of the castle town’s plan, too, was laid in this period. A castle whose layout was drawn by the man who supported Hideyoshi’s taking of the realm was this town’s starting point.

That castle was handed down, changing its lords. Hosokawa Tadaoki, who entered after the Kuroda, carried on the town plan Kanbei drew and ordered the castle town, making the form of the Nakatsu castle town that runs nearly to the present. Next the Ogasawara family advanced the ordering of the castle town, and in 1717 the Okudaira family, a hereditary daimyo bearing the guard of the western provinces, entered, and thereafter it remained the residence of the lords of the Nakatsu domain until the abolition of the domains in the Meiji era. The strategist’s castle moved into a stable age as the castle town of a hereditary daimyo.

And this castle town came to hold the face of a town of learning. The Okudaira’s Nakatsu domain founded a domain academy and encouraged Dutch learning, pouring strength into scholarship. From within that ground of learning grew a man such as Fukuzawa Yukichi, who would later write "An Encouragement of Learning." What decided the present form of the city area was the Heisei merger. In 2005 Nakatsu City incorporated Sanko Village, Honyabakei Town, Yabakei Town and Yamakuni Town in the upper reaches of the Yamakuni River, widening into a broad city area including the gorge. Beginning with Kuroda Kanbei’s castle, encouraging scholarship as the Okudaira’s castle town, and holding the upper reaches through the merger — this town’s form stands upon the past of the castle town and Dutch learning.

What characterizes Nakatsu is that, while the population keeps nearly flat over the fifteen years after the merger, inside it the turnover of generations is advancing. That the total population has hardly fallen can be read as an expression of the location of automobile-related factories and the like supporting the employment and inflow of young households. But behind that, those under fifteen fell gently, and the aging rate reached three in ten. Even where the head count of the whole town is kept, its inside is surely growing older.

The numbers of the living infrastructure, too, mirror this transition. Nakatsu City’s elementary schools bound the school network of the upper reaches through the 2005 merger, and have since been adjusted step by step in line with the fall of children. The Childcare Waitlist has moved at zero in recent years, but this is not so much the result of fully meeting demand as having a strong side of supply and demand balancing amid the number of children gently thinning. The town that opened as the castle town of Kuroda Kanbei and encouraged scholarship as the Okudaira’s castle town now keeps its population on the back of factory employment while, inside, turning over its generations. The total population flat, the children gently falling, the aging reaching three in ten — the figure of a castle town where these several movements proceed at once shows in the numbers. Numbers, alone, do not fix their meaning.

The functions Nakatsu holds are not one. There is the character of a castle town centered on Nakatsu Castle, whose layout Kuroda Kanbei drew and which the Okudaira family long governed, with the castle and the castle town’s plan still remaining at the town’s center. There is also the past of a town of learning, where Dutch learning was encouraged at the Okudaira’s domain academy, and from which a man such as Fukuzawa Yukichi grew. The city area bound through the 2005 merger holds in one city the castle town at the river mouth and the gorge of the upper reaches.

Nakatsu is a town where a strategist’s castle grew into a castle town of learning. From Kuroda Kanbei’s castle, to the Okudaira’s castle town and domain academy, and to the city area holding the upper reaches through the merger — the past in which "a castle whose layout Hideyoshi’s strategist drew became a castle town that encouraged scholarship under a hereditary daimyo" called forth the castle town and the ground of learning, and set the town’s skeleton. Precisely because there was the town plan of the castle the strategist drew, the later domain academy took root, and from it grew the writer of "An Encouragement of Learning." The chain by which the castle called forth scholarship, and scholarship raised people, runs through this town.