Chiyoda-ku

In the most recent Population Census the population is about 67,000 (66,680 in 2020). Over the twenty years from 36,035 in 2000, the number of people who sleep here at night nearly doubled. While many cities head toward aging and population decline, Chiyoda-ku is adding people in the opposite direction.

Go a step further and the composition, too, points the other way. Those under 15 rose from 3,528 (2000) to 8,976 (2020), and the share aged 65 and over fell from 20.9% to 16.3%. Municipalities whose aging rate falls over twenty years are almost nonexistent nationwide; this is a rare structure in which inflowing households diluted the elderly. The residential land price is around 3.425 million yen per m² (2026) — a level more than twenty times that of Kawagoe mentioned earlier, off by an order of magnitude. The Fiscal Capacity Index is 0.84 (FY2023), and taxable income per taxpayer doubled from 208 thousand yen (2000) to 411 thousand yen (FY2023), among the highest in the country. This lineup, where the digits diverge from other wards by one or two places, only makes sense once you follow the order in which the ward kept a vast non-residential zone — the Imperial Palace — at its center, thinned its housing, and only recently began returning people to the margins.

Chiyoda-ku’s skeleton was drawn around Edo Castle. As the seat of the Tokugawa shogunate, Edo Castle was placed here, and around it a castle town lined with daimyo residences was arranged. After the Meiji Restoration, Edo Castle became the Imperial Palace, and a vast palace grounds still sits at the ward’s center. The structure of holding a huge zone that is neither residential nor commercial at the heart of the town is the starting point that thins this ward’s nighttime population.

The Marunouchi–Otemachi area, once lined with daimyo residences, was used for a time after the Restoration as an army drill ground and the like, and the land was eventually sold off. Mitsubishi acquired it and built an office district modeled on London, nicknamed “Itcho London” (one-block London). Government offices then formed in Kasumigaseki, and the ward filled with functions — palace, offices, business — where people gather by day and leave by night. Behind the wartime collapse of the nighttime population into the thirty-thousand range lies this origin of land use, in which the share of residential land was small to begin with.

The reversal came in the 2000s. Amid the flow of return to the center, housing supply such as tower apartments advanced around Marunouchi and across Bancho, Kudan and Kanda, and night residents began to return to a ward that had been a daytime city. Housing inserted into the margins of the business district appeared in the numbers as a doubling of the population and a rise in the number of children.

In Chiyoda-ku, the population’s reversal appeared as a rise in the number of children. In declining regional cities, falling child counts bring school consolidations, but Chiyoda-ku walks the reverse. There are 11 elementary schools in the ward, and in a ward where consolidation was once debated amid falling pupil numbers, the school network is shifting to the side that catches the residents’ return.

The childcare waitlist is, most recently, zero. But this zero carries the opposite meaning from the “zero from a thinned absolute number of children” common in declining regional cities. In this ward, where those under 15 nearly doubled from 3,500 to almost 9,000, the zero is the result of keeping supply chasing rising demand. High tax revenue and fiscal capacity are part of what makes childcare supply for the growing number of households with children possible. Even with the same “zero waitlist,” the reading changes entirely when the population dynamics behind it point toward growth. A zero at the end of thinning children, and a zero made to keep pace amid doubling children — the same figure, yet what is happening in the ward is exactly opposite.

Chiyoda-ku holds, in a single ward, functions singular even within Japan. It holds the Imperial Palace at its center, and the head offices of major corporations and central government ministries concentrate in Marunouchi, Otemachi and Kasumigaseki. The ward was born on March 15, 1947, after the war, when the old Kojimachi-ku and Kanda-ku — their populations reduced to around thirty thousand by war damage — merged. The ward’s name derives from “Chiyoda Castle,” another name for Edo Castle.

What most symbolizes this ward is its day–night population gap. In one tally, while about 40,000 residents slept here at night, about 850,000 worked in the ward by day. A daytime figure twenty times the night — an expansion and contraction of population found nowhere else — appears as the consequence of land use given over to business concentration. The center of the castle town, a city of offices, a city of business, and now a ward where night residents have begun to return: the character of a place that carries the nation’s central functions has layered different functions in each era. By morning 850,000 pour in; by night only 40,000 remain. That extreme expansion and contraction is itself the texture of the ground that is Chiyoda-ku.