Odawara-shi

In the most recent Population Census the population is about 189,000 (188,856 in 2020). Over the five years from 194,086 in 2015 it fell by some five thousand. It is a city on the losing side of population within Kanagawa.

What is worth seeing here is that the number of children is thinning faster than the total. Those under 15 fell from 22,916 (2015) to 20,684 (2020), some two thousand fewer. Over the same period the share aged 65 and over rose from 27.7% to 30.0%, entering the stage of one resident in three being elderly. Households with children make up 18.7% (2020). The residential land price is in the 105,000-yen-per-m² range. The Fiscal Capacity Index is 0.91 (FY2023), falling just short of 1.0 — a structure that fills part of standard expenditure with the local allocation tax. The childcare waitlist moved nearly flat at a low level, from 3 children (2024) to 4 (2025). Population falling, children falling faster, the elderly above thirty percent — why these several flows advance at once cannot be read without going back to the origins of the castle town, the post station and the gateway.

Odawara’s skeleton is set on the castle town and the highway drawn around a castle. The first foundation is the castle. Beginning from a castle built by the Omori, around 1500 Ise Sozui (Hojo Soun) advanced onto this ground. Thereafter the Later Hojo held sway over the Kanto for five generations and about a hundred years, extending castle and town. The sogamae — the outer rampart of some nine kilometers in total length that ringed castle and town, built against the coming attack of Toyotomi Hideyoshi — was extraordinary for the scale of a castle of its day. What historical geography calls “a planned castle town with a castle at its core” was this town’s first foundation.

The second is the post station. In the Edo period, Odawara prospered as a post town said to be the foremost on the Tokaido. Odawara-juku was founded in 1601, the ninth station counting from Nihonbashi. Because the steep crossing of the Hakone passes lay ahead, before the next station of Hakone-juku, many travelers stayed a night here. The castle became the seat of fudai lords such as the Okubo, and, with the Hakone mountains at its back, was positioned as a key stronghold for the defense of Edo — the Kanto’s gateway.

The third is the railway of the modern era. In 1920 the Atami Line opened between Kozu and Odawara, and Odawara Station opened. In the 1923 Great Kanto Earthquake the station building and the Hakone Tozan Railway took heavy damage, but in 1927 the Odakyu opened between Shinjuku and Odawara, and Odawara established its standing as the gateway to Hakone tourism and hot-spring cures. A castle town, a post station, and the gateway to tourism — the advantage of a ground set against the Hakone mountains layered the same town with roles across the eras.

What characterizes Odawara is that, while the total population fell by some five thousand, the number of children fell by some two thousand — a faster pace than the total. It surfaces in the living-infrastructure figures as the front and back of advancing aging. The share of the elderly has reached thirty percent, and the town as a whole has entered deep into the stage of maturity.

Meanwhile, the childcare waitlist moved flat at a low level, from 3 children to 4. What must not be misread here is that a small waitlist does not necessarily mean only that childcare is generous. In a town where the absolute number of children has fallen by some two thousand, childcare demand itself shrinks, and there is a side on which supply more easily catches up with demand. Odawara stands at the entrance to the same structure seen in depopulating regional cities, where children thin — “a small waitlist as a result of the thinned absolute number of children.” Children falling faster, the elderly above thirty percent, the waitlist staying at a low level — these are not separate phenomena but one flow, the maturing of the population, translated into each of the figures. This figure, too, will be mistaken if read apart from its background.

Odawara holds several functions of its own. One is the structure of a castle town centered on the castle of the Later Hojo; the traces of the castle and the sogamae, and the layout of the town below, remain as historic sites, carving the town’s origin onto the map still. Another is its position as the Kanto’s gateway set against Hakone, gathering people and goods as a Tokaido post station in the Edo period and, from the modern era on, as the gateway to Hakone tourism.

In transport, the Tokaido Main Line, the Shinkansen, the Odakyu and the Hakone Tozan Railway gather at Odawara Station, a junction linking the center with the Hakone and Izu directions. It also has the face of a port town facing Sagami Bay, with fisheries and marine industry supporting part of the town. From a castle town to a post station, and on to a gateway of tourism — the advantage of “the Kanto’s entrance set against Hakone” has carried differing functions era by era. The castle, the post station and the railway junction all rest, in the end, on the same advantage of a ground just before the crossing of the Hakone passes. That position summoned, one after another, the roles of the Hojo’s castle, the Tokaido post station, and the Hakone gateway.