Koi (nyokan [court lady]): Originally, a koi was a court lady who served at the 'benden' (emperor's temporary place of sojourn [a temporary stay]) but later the koi served in the emperor's bed room and was elevated into the position of consort next to the nyogo.
更衣(女官)（こうい）…本来は「便殿」詰めの女官であったが、後に天皇の寝室にも奉仕して女御に次ぐ地位の配偶者に改められた。