The theatre play is set in the late Heian (794–1185) and early Kamakura period (1185–1333) in Japan. The main character is young adult Minamoto no Yoshitsune, from the Minamoto clan. Like previous chapters, it is a historical fiction, a world with supernatural powers and spirits (Mononokes). The idea was to create a story where the Oni (Japanese demons) were the origin of vampires, and eventually of the central character.[19] In the Heian period existed those called as Mononoke (spirits), and Mononofu, who were born between humans and Mononoke, and with special powers dominated both Mononoke and humans. The story from Mysteries of Yoshitsune spreads out when the member with inherited blood crossed over to Europe, and became the progenitor of the later vampires.