List of mergers in Tokyo

Here is a list of mergers in Tokyo, Japan since the Heisei era.

Mergers before April 1, 1999

• 1917 – Hachiōji town became an [independent] city, leaving Minamitama District.
• 1932 (establishment of Dai-Tōkyō-shi, "Greater Tokyo City") – 82 towns and villages were merged into Tokyo City and consolidated into 20 new wards.
• 1936 – The villages of Kinuta and Chitose were merged into Tokyo city and integrated into Setagaya ward.
• 1941 – Komiya town was merged into Hachiōji city.
• In 1943 - Tokyo City (Tōkyō-shi) was abolished, and the government of the larger Tokyo Prefecture (Tōkyō-fu), henceforth the Tokyo Metropolis (Tōkyō-to), assumed the direct administration of the former city. Since 1943, no city in Japan has had the name Tokyo.
• March 1947 - The 35 wards of former Tokyo city were consolidated into 22 wards.
• May 1947 – The 22 wards were transformed into quasi-municipal special wards.
• August 1947 – The special ward of Nerima was split off from Itabashi.
• 1955 – The villages of Hirai and Ōguno merged to establish Hinode village.
• 1955 – The villages of Yokoyama, Moto-Hachiōji, Ongata, Kawaguchi, Kasumi and Yui were merged into Hachiōji city.
• 1956 – The villages of Miyake, Tsubota and Ako (all three in Miyake Subprefecture) merged to newly establish Miyake village.
• 1958 – Machida town and the villages of Tadao, Tsurukawa and Sakai merged to newly establish Machida city.
• 1959 – Asakawa village was merged into Hachiōji city.
• 1963 – Sunagawa town was merged into Tachikawa city.
• 1964 – Yugi village was merged into Hachiōji city.
• In 1995 - the city of Akiruno was established by the merger of the city of Akigawa and the town of Itsukaichi.

Mergers from April 1, 1999 to Present

• On January 21, 2001 - the city of Nishi-Tōkyō was established by the merger of the cities of Hōya and Tanashi.

Name changes

• 1928 – Chōfu village (Chōfu-mura) in Ebara county becomes a town and is renamed East Chōfu town (Higashi-Chōfu-machi; note: there had been a Chōfu-machi/Chōfu town in North Tama county, Kanagawa since 1889. There had also been Chōfu-mura/Chōfu village in West Tama county (Nishitama-gun), Kanagawa since 1889. North (Kita-), South (Minami-) and West Tama counties (Nishi-Tama-gun) were transferred from Kanagawa to Tokyo in 1893, so that there were three different municipalities named "Chōfu" (two -mura, one -machi) in Tokyo until 1928. Eventually, East Chōfu town, Ebara became part of Tokyo city in 1932, Chōfu village, West Tama became part of Ōme city in 1951 and Chōfu town, North Tama became part of Chōfu city in 1955)
• 1970 – Murayama town (Murayama-machi) becomes a city and is renamed Musashi-Murayama city (Musashi-Murayama-shi; note: there was already a Murayama-shi/Murayama city in Yamagata/Dewa since 1954.)
• 1970 – Yamato town (Yamato-machi) becomes a city and is renamed Higashi-Yamato-shi ("East Yamato city"; note: there was already a Yamato-shi/Yamato city in Kanagawa since 1959. Geographically, Higashi-Yamato-shi lies almost exactly north of Yamato-shi; the Higashi/"East" (東) represents the Tō (東) in Tōkyō – Higashi-Yamato-shi is "Tokyo's Yamato City". There had also been a Yamato town in Saitama which was renamed as Wakō city in 1970.)
• 1970 – Kurume town (Kurume-machi) becomes a city and is renamed East Kurume city (Higashi-Kurume-shi; note: there was already a Kurume-shi/Kurume city in Fukuoka, one of the first 40 cities of Japan in 1889/90.)

Notes

• There are several technical differences between two types of mergers: hennyū gappei, "incorporating/absorbing mergers", where one or several municipalities merge into another that continues to exist, and shinsetsu gappei, "new establishment mergers", where two or more municipalities dissolve to establish a new one which may bear the identical name of one of its predecessors. In the latter case – regardless of naming –, for example, municipal institutions (mayor and assembly) lose their mandates, and new elections must be held.
• County/district governments were dissolved in the 1920s following a 1921 initiative by the Hara Cabinet and are not mentioned in the list after their abolition as administrative units.