Sanpu (literally, three fu) (三府)
Sanpu refers to three prefectures classified as 'fu.'
It means Tokyo-fu, Kyoto-fu, and Osaka-fu before metropolitan government system was in effect.
It refers to the place where the ancient provincial capital of Mikawa Province was located. Ko-cho, Toyokawa City, Aichi Prefecture.
Three prefectures classified as 'fu'
Sanpu, the three urban prefectures, refers to Tokyo-fu, Kyoto-fu and Osaka-fu, which existed from the Meiji to the Showa periods. It also refers to a collective term for Tokyo, the capital of Japan, and Kyoto and Osaka, either of which could be a substitute for Tokyo. Out of the nine 'fu' under the Fu-Han-Ken Sei (the domain and prefecture system), six 'fu' were changed into 'ken' under Haihan-chiken (abolition of feudal domains and establishment of prefectures) published in 1874, which resulted in three 'fu,' which remained in the prefectural system under Meiji Constitute. Tokyo-fu remained until it was changed into Tokyo-to when metropolitan government system became in effect in 1943.
The central places of the three 'fu' (prefectures) has been of great importance and regarded as the three major cities in Japan since the Edo period.
The ancient provincial capital of Mikawa Province
The place where the ancient provincial capital of Mikawa Province (present-day east of Aichi Prefecture) was located is called Sanpu. Sanpu (三府) sometimes expressed in different characters as "参府." It means Kokufu (the offices), Fuchu (the location), and Funai (the area) of the provincial government capital of Mikawa Province (also known as Sanshu). It was located around present-day Ko-cho, Toyokawa City, Aichi Prefecture. It is the same manner as Kofu (literally, 'fu' of Kai Province) in Yamanashi Prefecture and Sunpu (literally, 'fu' of Suruga Province) in Shizuoka Prefecture. However, few people call that place Sanpu.