Junshaku is a customary practice of conferring a Court rank on kurodo (chamberlain), which developed in the early Heian period.
Junshaku is promoting one of the government officials of the sixth rank belonging to the divisions of Shikibu, Minbu (popular affairs), Geki (Secretary of the Grand Council of State), or Shiki to Jugoi (Junior Fifth Rank), in accordance with tenure (the number of years in service), at Jimoku (ceremony for appointing officials) performed by Daijokan (Grand Council of State) on every New Year's day. Junshaku of government officials of the sixth rank at Kurododokoro (the Chamberlain's office) is a well-known case of Junshaku. It is said that kurodo with the longest tenure, in other words gokuro, was ennobled every year with the exception of the cases where the kurodo was allowed to remain in office (joryu), and that most of them made the transition to kokushi (provincial governors). The promoted kurodo is said to have left the court and assumed the position of Kurodo no goi. Those who decided not to leave the court made a point of not being ennobled in order to remain at the sixth rank, and restarted a career as kurodo at the lowest rank. Thus, the custom of gekitai (that the sixth rank kurodo declines the peerage and gets demoted to Shinkurodo in order to remain as Tenjobito) sprang up.