Arakawa-ku

In the latest Population Census the population is about 217,000 (217,475 in 2020). Over the five years from 212,264 in 2015, it gained more than five thousand. Though small in scale among the twenty-three wards, it is a ward that has steadily extended its population.

What I want to note here is that the number of children too is increasing. Those under 15 rose from 23,588 (2015) to 24,470 (2020), about nine hundred. In the same five years, the share aged 65 and over moved nearly flat, from 23.1% to 23.2%. The household-with-children share is 16.6% (2020), a level exceeding Kita-ku’s 14.5%. The land price of residential areas is about 670,000 yen per m². The Fiscal Capacity Index is 0.34 (2023), below 1.0, but this is due to the mechanism by which the twenty-three wards are under the ward-finance adjustment system, where much of a ward’s tax revenue is once gathered by the metropolis and redistributed — a consequence of a design that does not presuppose a ward covering all expenditure on its own. The Childcare Waitlist fell from 33 (2024) to 11 (2025). Why households raising children live thickly on this lowland does not fall into place without going back to the factories that relied on the river’s water and the wholesale district of old textiles.

Arakawa-ku’s skeleton is the history of industry and wholesalers gathered relying on the river’s water. In the Edo era, this area was mostly farming villages. What changed the flow was water. From the Meiji era on, seeking the abundant water of the Arakawa — before the 1965 River Act, the present Sumida River was called by this name — many factories sited themselves on this riverside. The process that economic geography would call “a locational condition of water that called in industry” is this ward’s first foundation. In particular, Minami-senju is held to be the birthplace of Japan’s wool industry and the birthplace of paperboard, known as a place where several modern industries first cried out.

The second foundation is the wholesale district. Around the early Taisho era, businesses handling the old textiles that became unneeded in factories began to gather around Nippori and Mikawashima. This is held to be the rise of the later Nippori Textile Town, and the concentration of wholesalers dealing in textiles, alongside the riverside industry, shaped this ward’s character. And in 1932, with the expansion of the urban area of Tokyo City, the four towns of Minami-senju, Nippori, Mikawashima, and Ogu merged and Arakawa-ku came into being. The ward name derives from the Arakawa flowing along the ward’s northern edge. The third foundation is transport. The Toden Arakawa Line, running within the ward, has as its predecessor the Oji Electric Tramway, which opened the Otsuka–Asukayama section in 1911, and the whole Waseda–Minowa line opened in 1930. As lines of the Toden continuing from before the war were abolished one after another, this alone keeps running as the only streetcar still extant in the city. Riverside industry made the town, the wholesale district deepened its character, and a single streetcar keeps carrying that era — this ward’s form stands upon a history in which river, industry, and transport are layered many times over.

What characterizes Arakawa-ku is that, while the total population rose by five thousand, the number of children too rose by nine hundred. A small ward among the twenty-three has extended in the same direction in both total and number of children. The household-with-children share of 16.6% exceeds adjacent Kita-ku’s 14.5%, and one can sense that young households live with a certain thickness on the riverside residential land.

The Childcare Waitlist fell from 33 (2024) to 11 (2025). A decrease in the waitlist amid children continuing to increase is the opposite in meaning to the “result of the absolute number of children thinning,” common to regional cities in population decline. That the number on the waitlist fell in a ward where children increase can be read as there having been a year in which supply was made to catch up to the ever-extending childcare demand. But the waitlist is a figure that swings year to year with the progress of supply development, and the trend cannot be judged by the increase or decrease of a single year alone. So the decrease from 33 to 11 takes on meaning only when matched against the thickness of a household-with-children rate of 16.6%. Take out only one figure and one will misread this downtown’s room to grow.

Arakawa-ku holds several functions of its own. One is the memory of industry grown from riverside industry, conveyed by the Minami-senju area held to be the birthplace of the wool industry and of paperboard. Another is the Nippori Textile Town, grown from old-textile wholesalers in the Taisho era, which, as a concentration dealing in textiles, still inscribes this ward’s character. And the third is the Toden Arakawa Line — the Tokyo Sakura Tram — running east to west through the ward, which, as the only streetcar still extant in the city among the Toden lines continuing from before the war, keeps carrying the town’s time just as it is.

Arakawa-ku has changed the functions it carries era by era — from riverside industry, to the old-textile wholesale district, and further to residential land lined along the streetcar route. The factories, the wholesalers, and the present residential land are all, at root, set upon the same condition — “lowland blessed with the river’s water.” The river’s water called in factories, the old textiles that came out of those factories grew the wholesale district, and the Toden that alone survived the wave of abolition still runs along that route. A single condition — riverside lowland — has, in order, called in industry, wholesalers, and the streetcar.