Arakawa, Tokyo Arakawa, Tokyo Arakawa has sister-city relationships with Donaustadt in Vienna, Austria, and with Corvallis, Oregon, U.S. Domestically, it has similar relationships with nine cities, towns and villages. As of May 1, 2015, the ward has an estimated population of 208,763, and a population density of about 20,550 persons per km². The total area is 10.16 km². Arakawa is in the northeastern part of Tokyo. The shape is long and narrow, stretching from west to east. The Sumida River forms the northern boundary. The ward is surrounded by five other special wards. To the north lies Adachi; to the west, Kita;
Japanese gunboat Sumida (1939) Japanese gunboat Sumida (1939) "Sumida" was the second of two vessels in the river gunboats authorized under the 3rd Naval Armaments Supplement Programme of 1937. "Sumida" had a hull with an overall length of and width of , with a normal displacement of 338 tons and draft of . She was propelled by two Kampon steam turbine engines with two boilers driving two shafts, producing and had a top speed of 17 knots. The ship was armed with one /28 cal. gun and one 25mm machine gun. " Sumida" was laid down on 13 April 1939 and launched 30 October