Consequently, the remaining possibility was Imperial Princess, although the title of Hi in the Heian period got lower, the advantage for an Imperial Prince whose mother was from Imperial family having prior right to succession to the Imperial throne since ancient time was valued for aiming at family succession to the throne.
従って、残りは内親王となるが、平安時代の妃は結果的には成功しなかったものの、古代以来皇位継承の優先権があるとされた皇族を母とする親王による皇位の直系継承を目指したものと考えられている。