Koga-shi

In the latest Population Census the population is about 139,000 (139,344 in 2020). What I want to note first is that the steep rise of more than eighty-six thousand, from 58,727 in 2000 to 145,265 in 2005, is not the result of people naturally increasing. It owes to the 2005 new merger of the old Koga City and two towns, and the step in the figures mirrors that merger. The old Koga City before the merger was about sixty thousand, and joining with the surrounding towns it widened both its municipal area and its population at a stroke.

On that basis, looking at the post-merger content, it stayed at a decline of about six thousand over fifteen years, from 145,265 in 2005 to 139,344 in 2020 — roughly close to flat. On the other hand, those under 15 fell by a little over four thousand four hundred, from 20,651 in 2005 to 16,213 in 2020. The share aged 65 and over rose from 17.0% (2000) to 28.5% (2020). The household-with-children share is 20.8% (2020), the Childcare Waitlist has been zero in recent years, and the Fiscal Capacity Index was 0.72 in fiscal 2023. The border town widened by merger holds its total while quietly growing older within. Why this is so makes sense only by returning to the history of the Kubo and water transport.

Koga’s skeleton was set by one power that moved to this land in the Muromachi era. Around the Onin years, Ashikaga Shigeuji, who had been the Kamakura Kubo, left Kamakura amid the turmoil of the Kanto and in 1455 moved his seat to this land of Koga. Thereafter this house called itself the “Koga Kubo” and remained, for some hundred and twenty years, one center of the politics of the eastern provinces. A small border land became the seat of a power glaring at the eastern provinces — this is this town’s first foundation.

In the Edo era, Koga was laid out as the castle town of the Koga Domain. Koga Castle, one of the foremost in scale in the Kanto, was built, and a town spread in its castle precinct. But it was not the castle alone that set Koga’s character. The water transport of the great rivers the Watarase and the Tone, and the Nikko Kaido linking Edo and Nikko, met at this land. As a node where the land highway and the river boat transport met, Koga gathered people and goods. Koga-juku in the castle precinct was also a post town that flourished along that highway.

And entering the modern era, the rivers of this area took on another role. The Watarase Retention Basin, set up to cope with mine pollution, spreads to the west of the city, and later became a wetland registered under the Ramsar Convention. Beginning with the seat of the Koga Kubo, becoming the castle town of the Koga Domain, and flourishing as a node of the highway and water transport — that the river and the highway met at this land drew the seat of power and the post town alike here.

What characterizes Koga-shi is that, while the post-merger total population holds roughly flat, within it the children decrease and aging advances. That the total has hardly fallen over the fifteen years after the merger can be read as an expression of how the location — on a rail line heading toward Tokyo — has roughly balanced the inflow and outflow of young households. Yet behind that, those under 15 fell by a little over four thousand four hundred, and the aging rate rose by eleven points over twenty years. Even with the headcount of the whole town held, its content is certainly growing older.

The figures of living infrastructure mirror this transition too. Elementary schools jumped from seven to twenty-three at the 2005 merger, the school networks of the joined towns bound together as they were. They have since held at twenty-three, and even as children gently decrease, the school network dispersed across the widened municipal area is maintained. The Childcare Waitlist has held at zero in recent years. The town that glared at the eastern provinces as the seat of the Koga Kubo and flourished as a node of the highway and water transport now holds its total by its rail-line location while quietly turning over the generations within. The total population is flat, children decrease, and aging advances. The present of a border town that holds its total on a rail line is not something to be spoken of by pulling out any single number. Only where the three are laid over one another does the town’s present come into view.

In Koga several faces the river and the highway drew in overlap. One is the history of the land of the Koga Kubo, which became the seat of the eastern provinces in the Muromachi era — a border land that was, for a time, one center of the politics of the Kanto. Another is the character of a node where the water transport of the Watarase and Tone and the Nikko Kaido met, gathering people and goods with both the land highway and the river boat transport at its back. And the position at the westernmost edge of the prefecture still keeps the character of a traffic key point, neighboring several prefectures and a metropolis.

From the seat of the Koga Kubo, to the castle town of the Koga Domain, to a post town of the Nikko Kaido and a node of the river, and on to a rail-line city widened by merger. That the river and the highway met at this land drew the seat of power and the post town alike to this bank of the Watarase. The seat of a Kubo that glared at the eastern provinces is now on the rim of a commute neighboring three prefectures and a metropolis. From the seat of power to a post town, from a node of the river to a rail-line city, this town has kept its seat on the bank of the Watarase, changing its role with each era.