Saiwai-ku (幸区) is one of the 7 wards of the city of Kawasaki in Kanagawa Prefecture, Japan. As of 2010, the ward had an estimated population of 153,255 and a density of 15,250 persons per km2. The total area was 10.05 km2.
Geography
Saiwai Ward is located in eastern Kanagawa Prefecture, in the center portion of the city of Kawasaki, bordering on Tokyo to the north and Yokohama to the south.
Archaeologists have found numerous Kofun period remains at numerous locations in what is now Saiwai-ku, indicating a long period of human settlement. Under the Nara periodRitsuryō system, it became part of Tachibana District Musashi Province. In the Edo period, it was administered as tenryō territory controlled directly by the Tokugawa shogunate, but administered through various hatamoto, and was the center of a prosperous farming area adjacent to Kawasaki-juku, a post station on the Tokaido highway connecting Edo with Kyoto.
After the Meiji Restoration, the area urbanized due to its proximity to Kawasaki Station on the Tokaido Main Line. Saiwai Village within Tachibana District in the new Kanagawa Prefecture was created on April 1, 1889 through the merger of eight smaller hamlets. In the early twentieth century, the area was dominated by factories; notably Meiji Sugar and Toshiba. The area was largely destroyed by the Great Kanto earthquake of 1923, but was soon rebuilt. The area was annexed by the neighboring city of Kawasaki in two stages in 1927 and in 1937. The area was heavily damaged by American bombing during World War II.
Saiwai Ward was established with the division of Kawasaki into wards on April 1, 1972.