Emperor Yūryaku
According to "Kojiki" and "Nihonshoki", he was a son of Emperor Yūryaku and his consort Katsuragi no Karahime. Seinei's full sister was Princess Takuhatahime. His name in birth was . It is said that the color of his hair was white since birth. After the death of his father, Seinei won the fight against Prince Hoshikawa, his brother, for the throne and so succeeded his father.