Hoshi (保司)
Hoshi refers to officers of provincial government who administered ho, which was a type of Kokugaryo (the territories governed by a provincial government office) in medieval Japan.
Ho (shogunal demesne) and Sho (private land)
Although a theory has it that ho was a small-scale shoen (manor), ho was originally a shogunal demesne which was distinguished from sho, which were private lands.
On September 14, 1186, according to Azumakagami (The chronology of the Kamakura bakufu [Japanese feudal government headed by a shogun]), MINAMOTO no Yoritomo appointed TAIRA no Yasuyori as hoshi of Oe no ho, a shogunal demesne in the Province of Awa.
Therefore nengu (land tax) collected from Oe no ho was customarily deposited with the Kuraryo (Bureau of Palace Storehouses) of the Imperial Court.
(Azumakagami, vol. 8, September 16, 1185)