Okayama-shi

In the 2020 Population Census, Okayama’s population is 724,691. At about 725,000, over the five years from 719,474 in 2015 it added some five thousand. While many designated cities enter a plateau, it remains on the side that gently rises.

Yet the number of children points the other way. Those under 15 fell from 97,043 (2015) to 92,756 (2020), more than four thousand fewer. Over the same period the share aged 65 and over rose from 24.3% to 25.6%. Behind a gently rising total, the composition is steadily shifting its center of gravity toward the older end. Households with children make up 19.9% (2020). The residential land price is around 35,000 yen per m² (34,800 yen), a restrained level even set beside the prefectural capitals of the same Chugoku and Shikoku regions. The Fiscal Capacity Index is 0.74, a designated city with a structure in which part of standard expenditure is filled through the local allocation tax. The childcare waitlist is 0 (2025), with supply abreast of demand. What is worth keeping in view, though, is that these are averages for a city of 700,000. The municipal area is divided into four wards — Kita, Naka, Higashi and Minami — and the south, where the reclaimed land spreads, and the north, heir to the castle town, differ greatly in character. The gaps between wards are flattened out and do not appear in this single figure. Why the city takes this shape cannot be read without going back to the origins of the castle town and the reclamation.

Okayama’s skeleton stands on two artificial grounds — the town division drawn in the castle town, and the reclaimed land that turned sea into land. In the Tensho era, Ukita Naoie moved his residence to the castle on Ishiyama, greatly rebuilt it, and set about building a castle town. His son Hideie carried this on, completed Okayama Castle, and ordered the castle town. The skeleton of the castle town of Okayama was set down here. It is a textbook case, in historical geography, of a town division drawn by daimyo power forming the center of a city.

After Sekigahara, the castle lord changed — by way of the Kobayakawa — to the Ikeda house. In 1632, Ikeda Mitsumasa entered with a fief of 315,000 koku, and thereafter this city was the Ikeda house’s castle town and the center of Bizen through the early modern period. Among the Ikeda house’s undertakings, the one that decided the ground of the city was reclamation. The shallow sea of Kojima Bay, spreading between the Asahi River flowing just east of the castle town and the Yoshii River further east, was turned to land in stages. As a result of large-scale new-paddy development, a great granary was formed in the south of the Okayama Plain. Where there had been sea became paddy, and in time changed into built-up area — the ground on the city’s south side was made not by natural landform but by the human hand of reclamation. In 1700 the lord Ikeda Tsunamasa completed Korakuen, one of Japan’s three great gardens, just east of the castle town.

Entering the modern era, in 1889 Okayama adopted municipal status with an area of 5.77 square kilometers and a population of just over forty-seven thousand. In 2009 it became the country’s eighteenth designated city, with four wards — Kita, Naka, Higashi and Minami — placed. The town division drawn in the castle town, the plain widened by reclamation, and the terminal where the Sanyo Shinkansen, the conventional lines and the streetcar gather — this city’s form stands on an origin of turning sea into land and drawing in transport.

What characterizes Okayama is that while the total population rose by five thousand, the number of children fell by more than four thousand. The gain in the total and the decline in children run at once. Households with children make up 19.9%, neither outstandingly thick nor thin as the average of a 700,000 city.

The childcare waitlist has fallen to 0 (2025). But this “zero” allows two readings. Is it a result of increasing supply to keep abreast of demand, or a result of the demand side easing as the absolute number of children fell by four thousand — probably both overlap. Municipalities pressing the waitlist near zero are increasing even in metropolitan rings such as Kobe City and Osaka City, but the same “zero” shifts entirely in meaning with whether children behind it are rising or falling. In Okayama’s case, it fits to read it as a balance amid a declining absolute number of children. Children gently decline, the elderly share crosses a quarter, and yet the total holds at a slight gain — in a 700,000 city where those several flows run at once, the waitlist too converges small. But this too is an average across four wards; between the reclaimed south and the castle-town north, the circumstances of children and childcare cannot be the same. Take the single word “zero” as the same across all four wards, and it sweeps your feet out from under you.

In Okayama, functions of differing character are layered. One is Korakuen, set by Ikeda Tsunamasa just east of the castle town, and Okayama Castle, which was the castle town’s center, leaving the early-modern legacy of a daimyo garden and a castle at the center of the built-up area. Another is the granary of the southern Okayama Plain, made from the sea by the Ikeda house’s reclamation, which still supports the southern half of the municipal area as it changed from paddy to built-up area. Okayama Station, moreover, is one of the leading terminals of the Chugoku region, where the Sanyo Shinkansen, the conventional lines and the Okayama Electric Tramway streetcar gather.

Okayama was designated a designated city in 2009, holding prefecture-level administrative authority on its own. From a castle town to a reclaimed granary, and on to a four-ward city centered on a transport node — the origin of “a plain that turned sea into land and gathered transport there” has carried different functions in each era. The castle, the garden, the paddy and the built-up area all rest, in the end, on the artificial ground of the castle town’s division and the reclaimed land. Rather than following the natural landform, the origin of turning sea into land summoned function after function. The 700,000 city of Okayama stands on that accumulation of artificial ground.