Historically, during the
Edo period, the
Tokugawa shogunate established around the nine largest cities in Japan, and 302 elsewhere. When the Meiji government began to create the prefectural system in 1868, the nine bugyō-ruled zones became , while the township-ruled zones and the rest of the bugyō-ruled zones became . Later, in 1871, the government designated
Tokyo,
Osaka, and
Kyoto as
fu, and relegated the other
fu to the status of
ken. During
World War II, in 1943, Tokyo became a
to, a new type of pseudo-prefecture. Despite the differences in terminology, there is little functional difference between the four types of local governments. The subnational governments are sometimes collectively referred to as in Japanese, which is a combination of the four terms.
To Tokyo,
capital city of Japan is referred to as , which is often translated as "metropolis". The Japanese government translates as "Tokyo Metropolis" in almost all cases, and the government is officially called the "Tokyo Metropolitan Government". Following the capitulation of the
Tokugawa shogunate in 1868,
Tōkyō-fu (an urban prefecture like Kyoto and Osaka) was set up and encompassed the former city area of Edo under the
Fuhanken sanchisei. After the
abolition of the han system in the first wave of prefectural mergers in 1871/72, several surrounding areas (parts of
Urawa,
Kosuge,
Shinagawa and
Hikone prefectures) were merged into Tokyo, and under the system of (numbered) "large districts and small districts"
(daiku-shōku), it was subdivided into eleven large districts further subdivided into 103 small districts, six of the large districts (97 small districts) covered the former city area of Edo. When the ancient ritsuryō districts were reactivated as administrative units in 1878, Tokyo was subdivided into 15 [urban] districts
(-ku) and initially six [rural] districts (
-gun; nine after the
Tama transfer from
Kanagawa in 1893, eight after the merger of
East Tama and
South Toshima into
Toyotama in 1896). Both urban and rural districts, like everywhere in the country, were further subdivided into urban units/towns/neighbourhoods
(-chō/-machi) and rural units/villages
(-mura/-son). The yet unincorporated communities on the Izu (previously part of
Shizuoka) and Ogasawara (previously directly Home Ministry-administrated) island groups became also part of Tokyo in the 19th century. When the modern municipalities – [district-independent] cities and [rural] districts containing towns and villages – were introduced under the
Yamagata-
Mosse laws on local government and the simultaneous Great Meiji merger was performed in 1889, the 15
-ku became wards of
Tokyo City, initially Tokyo's only independent city
(-shi), the six rural districts of Tokyo were consolidated in 85 towns and villages. In 1893, the three Tama districts and their 91 towns and villages became part of Tokyo. As Tokyo city's suburbs grew rapidly in the early 20th century, many towns and villages in Tokyo were merged or promoted over the years. In 1932, five complete districts with their 82 towns and villages were merged into Tokyo City and organised in 20 new wards. Also, by 1940, there were two more cities in Tokyo:
Hachiōji City and
Tachikawa City. In 1943, Tokyo City was abolished,
Tōkyō-fu became
Tōkyō-to, and Tokyo-shi's 35 wards remained Tokyo-to's 35 wards, but submunicipal authorities of Tokyo-shi's wards which previously fell directly under the municipality, with the municipality now abolished, fell directly under prefectural or now "Metropolitan" authority. All other cities, towns and villages in Tokyo-fu stayed cities, towns and villages in Tokyo-to. The reorganisation's aim was to consolidate the administration of the area around the capital by eliminating the extra level of authority in Tokyo. Also, the governor was no longer called
chiji, but
chōkan (~"head/chief [usually: of a central government agency]") as in Hokkaidō). The central government wanted to have greater control over all local governments due to Japan's deteriorating position in World War II – for example, all mayors in the country became appointive as in the Meiji era – and over Tokyo in particular, due to the possibility of emergency in the metropolis. After the war, Japan was forced to decentralise Tokyo again, following the general terms of democratisation outlined in the
Potsdam Declaration. Many of Tokyo's special governmental characteristics disappeared during this time, and the wards took on an increasingly municipal status in the decades following the surrender. Administratively, today's special wards are almost indistinguishable from other municipalities. The postwar reforms also changed the map of Tokyo significantly: In 1947, the 35 wards were reorganised into the
23 special wards. In the occupation reforms, special wards, each with their own elected assemblies (
kugikai) and mayors (
kuchō), were intended to be equal to other municipalities even if some restrictions still applied. (For example, there was during the occupation
a dedicated municipal police agency for the 23 special wards/former Tokyo City, yet the special wards public safety commission was not named by the special ward governments, but by the government of the whole "Metropolis". In 1954, independent municipal police forces were abolished generally in the whole country, and the prefectural/"Metropolitan" police of Tokyo is again responsible for the whole prefecture/"Metropolis" and like all prefectural police forces controlled by the prefectural/"Metropolitan" public safety commission whose members are appointed by the prefectural/"Metropolitan" governor and assembly.) But, as part of the "reverse course" of the 1950s some of these new rights were removed, the most obvious measure being the denial of directly elected mayors. Some of these restrictions were removed again over the decades. But it was not until the year 2000 that the special wards were fully recognised as municipal-level entities. Independently from these steps, as Tokyo's urban growth again took up pace during the postwar economic miracle and most of the main island part of Tokyo "Metropolis" became increasingly core part of the
Tokyo metropolitan area, many of the other municipalities in Tokyo have transferred some of their authority to the Metropolitan government. For example, the
Tokyo Fire Department which was only responsible for the 23 special wards until 1960 has until today taken over the municipal fire departments in almost all of Tokyo. A joint governmental structure for the whole Tokyo metropolitan area (and not only the western suburbs of the special wards which are part of the Tokyo prefecture/Metropolis") as advocated by some politicians such as former Kanagawa governor
Shigefumi Matsuzawa has not been established (see also
Dōshūsei). Existing cross-prefectural fora of cooperation between local governments in the Tokyo metropolitan area are the Kantō regional governors' association
(Kantō chihō chijikai) and the "
Shutoken summit" (formally "conference of chief executives of nine prefectures and cities",
9 to-ken-shi shunō kaigi). But, these are not themselves local public entities under the local autonomy law and national or local government functions cannot be directly transferred to them, unlike the "
Union of Kansai governments"
(Kansai kōiki-rengō) which has been established by several prefectural governments in the Kansai region. There are some differences in terminology between Tokyo and other prefectures: police and fire departments are called instead of , for instance. But the only functional difference between Tōkyō-to and other prefectures is that Tokyo administers wards as well as cities. Today, since the special wards have almost the same degree of independence as Japanese cities, the difference in administration between Tokyo and other prefectures is fairly minor. In Osaka, several prominent politicians led by
Tōru Hashimoto, then mayor of
Osaka City and former governor of
Osaka Prefecture, proposed an
Osaka Metropolis plan, under which Osaka City, and possibly other neighboring cities, would be replaced by special wards similar to Tokyo's. The plan was narrowly defeated in
a 2015 referendum, and again
in 2020.
Dō Hokkaidō is referred to as a or
circuit. This term was originally used to refer to Japanese regions consisting of several
provinces (e.g. the
Tōkaidō east-coast region, and
Saikaido west-coast region). This was also a historical usage of the character in China. (In Korea, this historical usage is still used today and was kept during the
period of Japanese rule.) , the only remaining
dō today, was not one of the original seven
dō (it was known as
Ezo in the pre-modern era). Its current name is believed to originate from
Matsuura Takeshiro, an early Japanese explorer of the island. Since Hokkaidō did not fit into the existing
dō classifications, a new
dō was created to cover it. The Meiji government originally classified Hokkaidō as a , and later divided the island into three prefectures (Sapporo, Hakodate, and Nemuro). These were consolidated into a single in 1886, at prefectural level but organized more along the lines of a territory. In 1947, the department was dissolved, and Hokkaidō became a full-fledged prefecture. The
-ken suffix was never added to its name, so the
-dō suffix came to be understood to mean "prefecture". When Hokkaidō was incorporated, transportation on the island was still underdeveloped, so the prefecture was split into several that could fulfill administrative duties of the prefectural government and keep tight control over the developing island. These subprefectures still exist today, although they have much less power than they possessed before and during World War II. They now exist primarily to handle paperwork and other bureaucratic functions. "Hokkaidō Prefecture" is, technically speaking, a redundant term because
dō itself indicates a prefecture, although it is occasionally used to differentiate the government from the island itself. The prefecture's government calls itself the "Hokkaidō Government" rather than the "Hokkaidō Prefectural Government".
Fu Osaka and
Kyoto Prefectures are referred to as . The Classical Chinese character from which this is derived implies a core urban zone of national importance. Before World War II, different laws applied to
fu and
ken, but this distinction was abolished after the war, and the two types of prefecture are now functionally the same.
Ken 43 of the 47 prefectures are referred to as . The Classical Chinese character from which this is derived carries a rural or provincial connotation, and an analogous character is used to refer to the
counties of China,
counties of Taiwan and
districts of Vietnam. == Lists of prefectures ==