Yokosuka-shi

In the most recent Population Census the population is about 390,000 (388,078 in 2020). From 428,645 in 2000 it fell by some 40,000, about 9%, over twenty years. In the same twenty years in which Chiyoda-ku doubled its people and Kawagoe edged up, Yokosuka instead lost them.

The drop in the number of children is larger still. Those under 15 fell from 56,940 (2000) to 40,747 (2020), some 16,000 fewer. Over the same period the share aged 65 and over rose from 17.4% to 32.1%, so roughly one resident in three is now elderly. The residential land price is in the 113,000-yen-per-m² range (2026), and the Fiscal Capacity Index is 0.75 (FY2023), a somewhat low ratio of own tax revenue for a Kanagawa city. Taxable income per taxpayer moved nearly flat, from 187,000 yen (in thousands, 2000) to 190,000 yen (in thousands, FY2023). Why these figures take this shape cannot be read without going back to the national role this town carried and the terrain of the Miura Peninsula.

Yokosuka’s town was made by taking on a national role. In 1853 Perry’s black-ship fleet arrived off Uraga, making this the first stage of Japan’s opening. Out of the need for coastal defense, the shogunate invited the French engineer Verny and, from 1865, began building the Yokosuka Ironworks (shipyard). Japan’s first stone dry dock was built here, and Yokosuka became the starting point of modern shipbuilding. What economic geography calls “dependence on a single large national function” was this town’s first foundation.

From the Meiji era on, Yokosuka was developed as a naval base; a town of about 63,000 at the time it became a city in 1907 swelled rapidly into the country’s largest naval-port city. Shipbuilding and the navy made jobs, and the town was bound tightly to that one point. But the end of the war in 1945 took away the naval port — the very base of the city’s founding — all at once. The former military property was requisitioned by the occupying forces, and the town stood at a grave crossroads.

After the war, part of the former naval port was carried over as bases for the U.S. Navy and the Maritime Self-Defense Force, and the shipbuilding technology turned toward private industry. Yet the mountainous terrain of the Miura Peninsula makes blocks of residential or factory land hard to create, and is ill-suited to receiving a large population. A town swollen by a national role walks its twenty-year population decline within a double constraint: that role shrinking, and the terrain blocking expansion.

The population decline surfaces as a number of pieces of living infrastructure. Elementary schools in the city fell from 49 in 2000 to 47 in 2023, two having vanished. It is not the fierce consolidation common to depopulating regional cities, but the school count edges slowly down, the opposite way from a town heading toward maintenance and expansion such as Kawagoe or Chiyoda. When children fall by 16,000, the school network thins to match in time.

The childcare waitlist fell from 6 children (2024) to 3 (2025). This movement toward zero owes more to the absolute number of children falling and capacity gaining slack than to a rise in childcare supply. The fall in the waitlist should not be shorted to “improved ease of raising children”; it needs reading together with the population dynamics that “the number of children itself is thinning.” The numbers are a mirror that reflects structure, not good or bad.

Yokosuka keeps functions of its own. The former naval port is now known as the harbor holding the U.S. Navy’s Yokosuka base (home of the Seventh Fleet) and the Maritime Self-Defense Force’s Yokosuka base (Self-Defense Fleet headquarters), still carrying a national security function. The Keikyu line (opened 1930) and the JR Yokosuka Line (opened from Ofuna in 1889) run through the town, linking it toward the center.

And in 2001 Yokosuka became a Core City, the city coming to hold prefecture-level administrative powers of its own. In tourism, the “naval-port cruise” that brings you close to MSDF and U.S. Navy vessels from the water is a sight found nowhere else. From the place where the country opened, to a shipbuilding town, to the country’s largest naval port, and on to a town of bases and Core-City status — the nature of “a port that takes on a national role” has changed the function it carries era by era. Even as the content of the role shifted from shipbuilding to defense, the nature of being a port bearing a national function has remained. The ironworks dock, the home port of the Seventh Fleet, and the naval-port sightseeing boat all rest, across the eras, on the same “port that takes on a national role.”