Shodaibu (aristocracy lower than Kugyo) (諸大夫)
Shodaibu is the name of class of government officials (especially one of low to medium rank), which was used from ancient times through medieval period to the early-modern times in Japan.
Under the original Ritsuryo system, shodaibu in ocho kokka (royal-court state) referred to jigenin (a lower rank of ancient Japanese nobility) of shii or goi (fourth or fifth rank), or government officials from minor aristocrats who only got promoted to shii (Fourth Rank). Top ranking officials for practical works, who supported the system of the dynasty state from tenth century to twelfth century, were mainly from the families of this class. After getting promoted again and again in bureaucracy and being appointed as goi, it was standard practice that they worked at local region as the head of kokushi (provincial governors) who went to the spot or Zuryo (the head of the provincial governors), they became the person responsible for ruling local region and invoked the power of the state and strived to make a fortune. Substantial operation of government-regulated organization or facility in Imperial Court was done by officials from this class. And also, as you can see that Sei Shonagon and Murasaki Shikibu who developed dynastic style literature were court ladies from this class, people from this class were the important bearers of the culture of dynasty. High-ranking warriors in this period also belonged to this class as officials for practical works in charge of military art, and supervised general samurai in samurai class by making them Kenin (retainers).
In recent times, Keishi (household superintendent) such as hereditary house of prince and Sekke (line of regents and advisers) were considered to be equivalent to this class in the Imperial Court and became the official title for them. In samurai family, fifth rank daimyo (Japanese feudal lords) and hatamoto (direct retainers of the bakufu, which is a form of Japanese feudal government headed by a shogun) were equivalent to this official court rank and called with this official title.