It is regarded that the reason for Princess Tashiraka becoming an empress to Emperor Keitai was largely due to political reasons that were to bring legitimacy to an Emperor of collateral lineage such was as her mother, Kasuga no Oiratsume no Himemiko.
手白香皇女が継体天皇の皇后となった理由として、母である春日大娘皇女と同じく傍系天皇の正当性を立てるための政略的な要因が大きかったと考えられている。