Kochi-shi

In the latest Population Census the population is about 327,000 (326,545 in 2020). In the five years from 337,190 in 2015, it fell by more than ten thousand. The prefectural capital of Tosa — Kochi Prefecture — much of the prefecture’s population gathers in this single city, but it has entered a phase of decline.

What to note here is the way the number of children and aging proceed. Those under 15 fell by more than four thousand, from 42,364 (2015) to 38,125 (2020). In the same five years the share aged 65 and over rose from 27.2% to 29.4%, nearing three in ten. The household-with-children share was 18.0% (2020). The Official Land Price for residential land is about 82,000 yen per m². The Fiscal Capacity Index is 0.63, with a structure that cannot fully cover standard expenditure with its own tax revenue and supplements the shortfall with the local allocation tax — a form widely common to regional prefectural capitals away from the major metropolitan areas. The Childcare Waitlist rose, at a low level, from 5 in 2024 to 9 in 2025. Why such numbers take this shape cannot be read without going back over the history of a castle town opened together with flood control.

Kochi’s skeleton is drawn upon a settling with water. In 1601 Yamauchi Katsutoyo, who entered Tosa for his service at Sekigahara, at first entered the coastal Urado Castle. But Urado was cramped for opening a castle town and was a flood-prone land, and it is said that the former lord, the Chosokabe clan, had also given up on large-scale castle-building there. So Katsutoyo decided to build a new castle on the inland Mount Otakasaka. In 1603 the main and second baileys were completed and he entered the castle.

This castle-building was, beyond the castle itself, one with flood control. Mount Otakasaka is held between two rivers, the Kagami and the Enokuchi, and to open a castle town the flow of the rivers had to be controlled. The castle and the castle town took shape together with this flood-control work. But because it suffered repeated floods, the castle’s name was changed from "Kochuyama Castle" to "Kochiyama Castle," which was abbreviated to "Kochi," and in time became the city’s name too. The town’s very name engraves a history of facing water. It is, in historical geography, an instance of adaptation to a natural condition remaining as a fossil in a place-name.

Entering the modern era, the Tosa Electric Railway opened within the city in 1904. It is among the oldest of the surviving trams, and at the Harimaya-bashi intersection, where three lines gather, there remains a rare diamond crossing where tracks cross on the level. Upon the castle town opened together with flood control, the tram has inherited the skeleton of the urban district.

What characterizes Kochi is that, while the total population falls by more than ten thousand in five years, the share of the elderly nears three in ten. Those under 15 fell by more than four thousand, and the share aged 65 and over rose from 27.2% to 29.4%. Even in the prefectural capital, where much of the prefecture’s population gathers, shrinking and aging proceed at once.

Within that, the Childcare Waitlist rose, at a low level, from 5 to 9. A growth of the waitlist in a phase where the absolute number of children falls can happen in a context different from the surge of childcare demand in major cities. If an increase in dual-income households, or a concentration of demand on a particular district or age, locally exceeds supply, a waitlist appears even as the total falls. The figure of 9 mirrors, behind the large flow of the prefectural capital’s shrinking, a fine mismatch of supply and demand — which district’s, which age’s childcare is short. Children fall, the share of the elderly nears three in ten, and yet locally childcare is short — even in a prefectural capital where much of the prefecture’s population gathers, the fall of children and a local shortage of childcare occur at once. The small move from 5 to 9 mirrors, behind the large flow of shrinking, a fine mismatch of which district’s, which age’s childcare is short.

In Kochi, several functions opened facing two rivers overlap. One is the castle town cored on Kochi Castle, set on Mount Otakasaka held between the Kagami and Enokuchi rivers, the urban district opened together with flood control that went on being the political and economic center of Tosa. Another is the Tosa Electric Railway, opened in 1904, where one of the oldest surviving trams runs through the urban district, and the level crossing at Harimaya-bashi, where three lines gather, has become a symbol of the town.

Kochi is the prefectural capital of Kochi Prefecture, and much of the prefecture’s population concentrates in this single city. From the castle town opened together with flood control to the modern city through which the tram runs — a single position, "Mount Otakasaka held between rivers," has re-loaded a different function age by age. The castle, the castle town, and the network of the tram are all, in origin, set upon the same lowland opened facing two rivers. The land opened by controlling water went on being the center of Tosa just so, and the castle, the castle town, and the network of the tram crossing on the level at Harimaya-bashi are all set upon the same lowland held between two rivers.