With respect to this change from "wagakimi" to "kimigayo," waka with the first line "wagakimi" is hardly seen other than in Kokin-Wakashu and Kokin Waka Rokujo (six volumes of Japanese poetry written in the middle of the Heian period) and, in poetry anthologies in the later age, overwhelmingly large number of wakas begin with the first line "kimigayo."
この「我が君」から「君が代」への変遷については、初句「我が君」の和歌が、古今和歌集と古今和歌六帖以外にはほとんどみられず、以降の歌集においては初句「君が代」が圧倒的に多い。