History
Onarimon Station opened on 27 November 1973 as a station of the Toei Subway (then Line 6, renamed the Mita Line on 1 July 1978), in the Nishi-Shinbashi 3-chōme district of Minato, Tokyo. The station name comes from the Onarimon intersection, where a gate of the same name once stood at the northern edge of the precincts of the great Tokugawa-family temple Zōjō-ji — originally a gate reserved for the Tokugawa shōguns' processions to the temple, since 1892 relocated to the edge of what is now the Tokyo Prince Hotel site, where it has survived both earthquake and wartime fire. Minato is one of the three central wards of Tokyo, created on 15 March 1947 from the merger of the former wards of Shiba, Azabu and Akasaka.
History summarized from Japanese & English Wikipedia · last reviewed 2026-05-25.
Notes
The Minato article notes that more than half of the roughly 150 foreign embassies presently in Japan are clustered within the ward, in part because Meiji-era authorities granted to foreign governments the sites of former daimyō residences in the area. Around the same Mita Line stretch as Onarimon, the article identifies Tokyo Tower, Zōjō-ji and Shiba Park as defining landmarks of the Shiba district.