|Debut|| Episode 1|
Murder at the Ball
|Japanese voice||Miyu Irino|
Seigen is rather tall. He has brown hair and darker brown eyes. He is oftern seen wearing a suit. He has fair skin.
Seigen seems cold but he isn't. Deep down he is very caring and shows that to Izumi. He dislikes Shinjurou though. When he takes possession of Bettenō he gives her various tasks to fool everyone that Rinroku Kaishō is dead and make Inga suffer, showing sadistic personality.