Kagami no Okimi may have been a member of the ozoku (kozoku (the Imperial Family) who are second- to the fifth-generation descendants of an emperor) judging by the title '王' (O, which was used by male descendants of emperors up to the fifth generation), although his name does not appear in any other historical source; moreover, according to one theory, he may have been a great-grandson of Emperor Senka.
鏡王は他史料に見えないが、｢王」称から2世-5世の皇族（王族）と推定され、一説に宣化天皇の曾孫という。