Todōfuken

In the Japanese language there are four different terms for prefectures. The prefectures are sometimes collectively referred to as to-dō-fu-ken (都道府県^?) in Japanese, which is a simple combination of the four terms.

Historically, during the Edo period, the Tokugawa shogunate established bugyō-ruled zones (奉行支配地) around the nine largest cities in Japan, and 302 township-ruled zones (郡代支配地) elsewhere. When the Meiji government began to create the prefectural system in 1868, the nine bugyō-ruled zones became fu (府), while the township-ruled zones and the rest of the bugyo-ruled zones became ken (県). 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 (see below).
Hokkaido is referred to as a dō (道).

Despite the differences in terminology, there is little functional difference between the four types of prefecture.