noun
one metropolis, one circuit, two urban prefectures, and 43 prefectures
Fixed phrase enumerating Japan's 47 prefectures by category: Tokyo (都), Hokkaido (道), Osaka and Kyoto (府), and the remaining 43 (県). Often used in administrative or educational contexts.
See also: 都道府県
日本の行政区画は一都一道二府四十三県から成る。
Japan's administrative divisions consist of one metropolis, one circuit, two urban prefectures, and 43 prefectures.
都道府県 is the general term for all prefectural-level divisions, while 一都一道二府四十三県 explicitly counts them by type.
A descriptive compound formed from numbers and administrative division types: 一都 (one metropolis), 一道 (one circuit), 二府 (two urban prefectures), 四十三県 (43 prefectures).