The killing scene in the prologue with the night view of cherry blossoms in the background was produced by the technique called Honkatori (writing poems quoted parts of old poems), quoting parts from "Sumida no haru geisha katagi" (also known as "Yoshibe UMENO") written by Gohei NAMIKI.
序幕の美しい夜桜を背景とする殺人場は、並木五瓶の『隅田春妓女容性』（梅の由兵衛）を下敷きにしたいわゆる本歌取の作品。