The ward was founded on March 15, 1947 and reached a peak resident population of 370,000 in 1965. The population has continued to decline and as of December 1, 2005, the ward had an estimated population of 252,011 with a density of 19,370 persons per km². During the day the population swells with commuters, resulting in a daytime population of around 430,000.
The total land area of Toshima is 13.01 km², sitting on a moderate plateau with a difference of 28 meters between the ward's highest and lowest points. Approximately 47% of Toshima's land is residential and 20% is used for commercial enterprises and public areas.
Though Toshima is a ward, it refers to itself as a city. The ward offices are located in Ikebukuro, which is also the commercial and entertainment centre of Toshima.
With a non-Japanese population of 15,516, or 6.16% of the total population, Toshima is one of the most international wards in Tokyo. Of the foreign population, 56% is of Chinese descent, 20% is of Korean descent, followed by Filipinos.
Evolving from a suburban agricultural district in the Edo period to the urban commercial centre that it is today, Toshima's growth was fueled by the construction of various rail lines built during the Meiji and Taishō periods.
The former Somei village, now part of Toshima, is the birthplace of the Somei Yoshino, Japan's most popular variety of sakura (cherry blossom tree). The variety was developed at the end of the Edo period.
The rail lines that run through or terminate in Toshima ward are:
Wipo Publishes Patent of Matsuzawa, Sakaiya Hiroshi and Toshima Kuniki for "Hardness Testing Device and Hardness Testing Method" (Japanese Inventors)
Oct 04, 2013; GENEVA, Oct. 4 -- Publication No. WO/2013/145111 was published on Oct. 3.Title of the invention: "HARDNESS TESTING DEVICE AND...
Wipo Publishes Patent of Palace Chemical, Kiyofumi Suzuki and Kiyoto Toshima for "Water-Soluble Cutting Fluid for Fixed Abrasive Grain Wire Saw, Cutting Method Using Same and Recycling Method Therefor" (Japanese Inventors)
May 04, 2013; GENEVA, May 4 -- Publication No. WO/2013/061695 was published on May 2.Title of the invention: "WATER-SOLUBLE CUTTING FLUID FOR...
Wipo Publishes Patent of Kobelco Research Institute and Toshima Manufacturing for "Oxide Sintered Body and Sputtering Target and Method for Manufacturing Same" (Japanese, Japanese Inventors)
Oct 03, 2013; GENEVA, Oct. 3 -- Publication No. WO/2013/141254 was published on Sept. 26.Title of the invention: "OXIDE SINTERED BODY AND...