Sumida-ku

In the most recent Population Census the population is about 272,000 (272,085 in 2020). Over the five years from 256,274 in 2015 it added nearly sixteen thousand. Even among the 23 wards, it is a ward that has held a clear upward trend.

What is worth seeing here is that the number of children is rising too. Those under 15 rose from 26,607 (2015) to 28,028 (2020), some fourteen hundred more. Over the same period the share aged 65 and over edged down from 22.7% to 22.1%. Population rises, children rise, the aging rate eases slightly — all three point up. Households with children make up 14.7% (2020), thicker than Taito-ku. The residential land price is around 517,000 yen per m², roughly half the level of neighboring Taito-ku. The Fiscal Capacity Index is 0.42, below 1.0, because the special wards pool part of their municipal taxes at the metropolitan level and have them redistributed through the Tokyo Metropolitan–Ward Financial Adjustment System; as a ward-alone figure it settles at this level. The childcare waitlist fell from 8 children (2024) to 5 (2025). Why the markers point up together rests on the water of the Sumida River: that water nurtured factories, and the factory town was burned twice by earthquake and air raid yet recovered each time — river, fire and revival, repeated, support from below the run of today’s figures.

Sumida-ku’s skeleton is made of factories gathered in reliance on the water of the Sumida River, and of recovery from two annihilations. The ward became a single administrative body after the war, formed in 1947 by the merger of the former Honjo Ward and Mukojima Ward. Long before, after the great Meireki fire of 1657, samurai residences and temples were moved to the Honjo side across the river, and urbanization advanced.

The foundation was manufacturing. After the Sobu Line opened in 1894, modernization accelerated with the spread of the transport network, and subcontracting factories increased. Under Meiji industrialization, while large factories of spinning, food and beer settled, countless small and mid-size factories in textiles, chemicals, machinery and printing gathered to form a great industrial clustering. What supported that clustering was the abundant water of the Sumida River: manufacturing processes that use large volumes of water held along this river — a clustering, in the terms of economic geography, centered on water as a resource.

This town was burned twice, to devastation. In the Great Kanto Earthquake of 1923 more than ninety percent of the former Honjo Ward was struck, and many lives were lost. In the war too, about seventy percent of the area burned, and hundreds of thousands lost their homes. Each time the town was rebuilt together with its factories, winning back its clustering of manufacturing. And in May 2012, Tokyo Skytree opened at Oshiage at the ward’s northern edge, a new tower rising over a town that had nurtured factories with the river’s water. The river’s water, countless factories, two annihilations and revival — this town’s form stands on the resource of the Sumida River and on the tenacity of recovering after each burning.

What characterizes Sumida-ku is that, while the population rose by sixteen thousand, the number of children rose by some fourteen hundred. That appears in the figures for living conditions in a form opposite to the consolidations common in regional cities that lost large populations. Households with children make up 14.7%, thicker than neighboring Taito-ku’s 11.9%. Into a downtown that developed as a factory town, households with children have returned and increased.

The childcare waitlist fell from 8 children to 5. A falling waitlist amid a still-rising number of children is opposite in meaning to the “zero from a thinned absolute number of children” common in regional cities of population decline. It reads as a mid-course figure of keeping supply abreast of demand while children and population both grow. The 5 is not a 5 left behind as children fell toward zero, but a 5 not yet filled while capacity widens for rising children. Read the same figure, and how it reads changes entirely with whether children behind it are rising or thinning. Children increase, the waitlist falls — Sumida’s living-conditions figures read straight as the consequence of a factory town winning back its thickness as a place to live.

Sumida-ku holds several functions of its own. One is the clustering of manufacturing, where small and mid-size factories of textiles, chemicals, machinery and printing gathered densely. Supported by manufacturing processes using the water of the Sumida River, it developed in strata from large factories down to small workshops. The other is Tokyo Skytree, standing at Oshiage at the ward’s northern edge, which since its 2012 opening has given a new landmark to the riverside factory town.

Sumida has shifted factories, housing and a tower onto the same location — the left bank of the Sumida River. From an era of nurturing factories with the river’s water, through being burned twice by earthquake and air raid and rebuilding each time, to a place to live that now increases its population at the foot of a tower — the condition of “a downtown blessed with the river’s water” has carried different functions, era by era. The factories, the rebuilt streetscape and the tower alike rest, in the end, near the same resource: the Sumida River. The river nurtured factories, that factory town was burned twice and recovered, and now increases people at the foot of a tower. One resource, the Sumida River, has summoned every function of this town in turn.