Rokui no Kurodo (a government post) (六位蔵人)
Rokui no Kurodo was a Ryoge no kan (class outside of the Ritsuryo system) post for officers at Kurododokoro (the Chamberlain's Office). This rank was placed immediately under Goi no Kurodo. Up to four to six persons were appointed to this post. The people performed secretarial roles, such as waiting on the Emperor. This post was also called Higero. Sixth-rank personnel were appointed to this post. However, persons at his post became tenjobito, who were permitted to enter the imperial court, and were also allowed to wear kikujin no ho (loose-legged pleated trousers used for formal wear in kikujin color). Therefore, the post was considered an honorable one because persons assigned under his post closely attended the Emperor.
The following is the order in which people qualified for this position: Hikurodo (people training to be a Kudo (Keeper of the Imperial Archives) of noble birth; Hikurodo, Shippei koto (vassals of the Sekke (line of regents and advisors); important Inshi posts (officials of the Retired Emperor's Office), Zoshiki (low-ranking functionaries); Jusei (Confucian scholars) who had passed difficult exams such as the Myobodo (study of codes); and Hogandai (administrative officials of the Retired Emperor's Office). No age limit was applied to the post. However, seating was arranged in the following order, corresponding to the order of appointment: Shin-Kurudo, Uji-Kurodo, Sashitsugi and Gokuro.
When a person had spent six years in the position of Gokuro, they were automatically promoted to the Fifth Rank. In these cases, if there were no Goi no Kurudo (Fifth Rank Kurodo) positions available, the person retired from his Kurudo post and became a Jigenin (lower ranking court official). Such people were named Kurodo no Goi (Fifth Rank Kurodo). However, if this person did not want to leave his position as a Tenjobito to become a Jigenin, he turned down the new rank, remained at the Sixth Rank and took a Shin Kurodo position once more. This practice was known as Gyakutai.
From medieval times onwards, the position of Goi no Kurodo gradually became a position occupied by Tosho-ke (hereditary court nobles) known as Meika (important families), and the practice of Rokui no Kurodo (Sixth Rank Kurodo) rising to Goi no Kurodo died out. Therefore, persons at the Rokui no Kurod post had to to either follow the 'Gyakutai' practice or become a jigenin. In later eras, no person experiencing Rokui no Kurodo reached the Court noble level. In early-modern times, the persons at this post, who were tenjobito but did not belong to Tosho-ke, were consistently considered those belonging to upper classes among jigenin. Descriptions of these people were recorded in the Jigekaden (A record of Jige (lower ranking court officials) genealogies, written by Kageumi MIKAMI).
In early-modern times, people in this post were permitted by the Emperor to use kinjiki (seven colors traditionally reserved for the imperial family and nobility), and even jigenin could use kane (oxidized liquid) to blacken their teeth, just like the Tosho-ke. The use of kinjiki was disallowed if someone became a jigenin, but they could continue to use kane throughout their lives.