Concerning this, in an interview with Saeko HIMURO, which was written down in the second volume of paper back, the author said, "I've had an uncomfortable feeling about the stories related to Prince Shotoku since my childhood, and one day I talked about this to Masako YASHIRO at an izakaya bar, she introduced the book "Kakusareta jujika (hidden cross)" written by Takeshi UMEHARA to me, and when I bought the book and read it next day, the whole image of the story came to my head."
これについて作者は文庫版2巻に収録された氷室冴子との対談で、「聖徳太子にまつわるエピソードに子供の頃から違和感を持っており、ある時、居酒屋で矢代まさこを相手にそういう話をしていたら、梅原猛の『隠された十字架』を紹介され、翌日それを買ってきて読んで、その時に全てのイメージが出て来た」と語っている。