"Jokan" (written as "上官" or "政官") is the collective term for government officers who were mainly engaged in clerical work in the Daijokan (Grand Council of State) under the Ritsuryo system (a system of a centralized government based on the Ritsuryo Code). Jokan was a broadly used term to indicate government officials such as the Shonagon (lesser councilor of state), Benkan (controller) and Geki (secretary of the Grand Council of State), who were the three directors of the Sankyoku (an assortment of three bureaus: the Shonagon bureau, Benkan bureau and Geki bureau, respectively), the Shi (an official in charge of records), the Shisho (an official in charge of miscellaneous documents) and lower ranking Kanjin (government officials) affiliated with the Sankyoku, or in other words, Jokan indicates all of the officials of the Daijokan except the Kugyo (top court officials) and the Giseikan (Legislature).
On the other hand, there are also examples contradicting the term as stated above, such as one that includes the post of Naiki (Secretary of the Ministry of Central Affairs) in charge of producing official documents like Shochoku (imperial rescripts) and Senmyo (imperial edicts) as a Jokan; an example that Jokan only indicates the Shonagon and Benkan but not the Geki; and a contrasting example showing that the term is limited to Kanjin lower in rank than Geki and Shi. In later years, however, the word Jokan was often used in the same sense as described in the last example, as illustrated by examples from the "Irohajirui-sho"(Kango-Japanese Dictionary from the Heian Period) where it is explained that Geki and Shi were referred to as Jokan. In addition, according to "Kakai-sho Commentary" by Yoshinari YOTSUTSUJI, the term originated from "Daijokan-hi-kan" (a government official reporting directly to the Daijokan, written as “太政官被官”) which contains the phonetic equivalent of "Jokan," sometimes written as "上官." In another case, in the "Myomoku sho" by Sanehiro TOIN, the pronunciation for the Chinese characters "政官" was said to be "ja-u-gu-ha-mu." Jokan was never adopted as an official word in the Ritsuryo-Kyakushiki (Laws of codes and ethics under the Ritsuryo system) however, and it is assumed that it was originally a slang word used within noble society.
Jokan dealt with practical works such as producing Daijokanpu (official documents issued by the Daijokan) and Senji (imperial decree), comparing and examining the precedents and producing records for Kuji and Gishiki (political operations and ceremonies of the Imperial Court) and handling personnel affairs. As Jokan also took charge of katanashi (a ritual for reading out bound documents on the government affairs before the actual work starts) in Kansei (Imperial meetings at a Daijokan agency) and Gekisei (meetings at a Geki agency), it increased its role and the status of Geki and Shi in particular much improved. Later on, the Joshu (director) of the Geki was called Kyokumu (Chief Secretary of the Daijokan), the Joshu of the Shi was called Kanmu and these two came to hold the highest positions in the Daijokan Kanjin aside from the Kugyo and Giseikan.