There is a theory that Hashihito no Himemiko ascended the throne as the princess of the previous Emperor but one and became an Empress after the death of Empress Saimei; however, for some reason her name was erased from the record.
斉明天皇の死後に間人皇女が先々代の天皇の妃として皇位を継いでいたのであるが、何らかの事情で記録が抹消されたという説である。