Tato means the wealthy farmer class that managed rice fields belonging to shoen (manor) or kokugaryo (rice fields governed by provincial government office) during Japan's Heian period. Tato (田堵) is also written in Chinese characters as "田刀" or "田頭." The term '田刀' first appeared in kenden-cho (note of Cadastral Surveys) of Echinosho, Omi Province owned by Ganko-ji Temple, as of December 895. The Chinese character "堵" included in "田堵" means a fence.
When the Ritsuryo system (a system of centralized government based on ritsuryo code) began to dissolve around the ninth-tenth century, some farmers amassed wealth by cultivating rice fields which they rented from others. These people were called Tato. Many Tato were local powerful clans, who were the descendants of Gunji (local magistrate) during ancient times, or ex-officials such as native provisional governors. With amassed wealth in hand, they further accumulated wealth by developing and managing additional land or subjected other petty farmers by lending rice seeds to them.
Then, when koden (rice fields administered directly by a ruler) located in kokugaryo was reorganized into myoden (rice fields owned by a nominal holder), Tato became the persons who undertook the management of myoden. Further, when reorganization into myoden reached shoen, Tato undertook the management of myoden located inside shoen as well. Thus, Tato were deeply engaged in the management of shoen/koryo (public land) and eventually gained the status of shokan (an officer governing shoen) or myoshu (owner of rice fields). It may be said that Tato played a large role in the process of establishing shoen koryo sei (The system of Public Land and Private Estates).
Depending upon the scale of land under their management, they were called either Daimyo Tato or Shomyo Tato. We can learn the reality of Tato from the following descriptions included in the "Shinsarugakuki," a book written in the eleventh century reflecting the social conditions at the time.
Dewa gon no suke (Deputy governor of Dewa Province) Toyomasu TANAKA is a specialist in agricultural management and at the same time, he is Daimyo Tato who manages several hectares of rice fields.'
He nurtures farmers while preparing for drought by maintaining farming tools and irrigation channels and leads farmers well when it's time to sow their seeds.'