Since around the 12th century, it emerged to take the place of traditional sento (a person who does practical business in the management of Shoen estates), azukari (government post), kengyo (one of shokans, officers governing Shoen manor), and jotsukai (a lower-ranked officer who governs Shoen manor).
12世紀頃から従来の専当・預(官職)・検校・定使などに代わって出現した。