Field note 001 / Map code

47 prefectures.
Four endings.

English makes Japan's top-level divisions sound uniform. Japanese keeps four different administrative labels visible in every address.

Geography2 minute readSource checked

Visual guide showing one Tokyo-to, one Hokkaido, two fu, and 43 ken

The short answer

One to. One dō. Two fu. Forty-three ken.

Japan has 47 prefectural-level governments. Tokyo alone uses 都 (to), Hokkaido alone uses 道 (dō), Kyoto and Osaka use 府 (fu), and the remaining 43 use 県 (ken).

Why English hides the pattern

English convention normally translates all four labels as “prefecture.” That is convenient, but it erases a distinction that Japanese place names retain. 東京都 is Tokyo-to, 京都府 is Kyoto-fu, and 青森県 is Aomori-ken.

The useful memory trick

Remember the four exceptions, not all 47 labels: Tokyo, Hokkaido, Kyoto, and Osaka. Everyone else is ken.