According to "Okina gusa," by Teikan KANZAWA, the Emperor was called the return of Shotoku Taishi (Prince Shotoku), since they had similarities such as a New Year's birthday and there was a fire on the day of birth, or that they both achieved a lot in politics; moreover, the famous historian and court noble, Motomitsu YANAGIHARA, referred to the Emperor as 'the first Saint Emperor since the peaceful era of Engi and Tenryaku.'
神沢貞幹の『翁草』によると生まれが元旦でそのとき火事があり且つ実績も立派という共通点から聖徳太子の再来といわれ、歴史家としても知られた公家の柳原紀光も「延喜・天暦の治以来の聖代である」と評したという。