Tonomo no Tsukasa (Palace Equipment and Upkeep Office) (殿司)
Tonomo no tsukasa was one of the kokyu junishi (twelve offices belonging to kokyu, empress's residence). They cleaned empress' residence and were in charge of interior lightings for the vehicle like a palanquin, lamp oil, kashoku, charcoal fuelwood and so on.
As the staffs, it consisted of one Tonomo no kami (corresponding to Jurokui [Junior Sixth Rank]) and two Tonomo no suke (corresponding to Juhachii [Junior Eighth Rank]) and six nyoju (a court lady in a lower rank).
With the reorganization of kokyu and the demise of kokyu junishi after the middle of the Heian period, Tonomo no tsukasa was incorporated into Tonomoryo (Imperial Palace Keeper's Bureau) and Tonomoryo began to send the staffs in Tonomo no tsukasa to Naishi no tsukasa (female palace attendants) and such a court lady was called court servant or court lady servant. The fixed number of court servants was 9 during the first half of twelfth century, but during the last half, seems to have been 12.