In 1904, Sadakichi KIDA published a thesis 'the history of Emperor Otomo with precedents of succession of empresses to the Imperial Throne' to suggest that there was a possibility that an empress was put up in the Jinshin year.
1904年（明治37年）に喜田貞吉が論文「女帝の皇位継承に関する先例を論じて大日本史の大友天皇本紀に及ぶ」を出して壬申年に女帝があった可能性を示唆した。