The origin of the Yiki Onna vampires is unrevealed.Yiki Onna vampires slew a Shinto priestess, earning the enmity of her daughter, Michiyo Watanabe.Michiyo used silver samurai swords and nitrate-dipped darts to destroy Yiki Onna vampires.Yiki Onna vampires were amongst the many vampires of the world summoned to Castle Dracula in the Carpathian Mountains of Transylvania to protect Dracula during his performance of the Ritual of Ascendance.While Juito stood alongside Dracula, the Yiki Onna attacked Noah van Helsing's vampire hunters -- Benjamin Alomii, Blade, Enzo Ferrara, Lucas Telling-Stone, Noah van Helsing, and Michiko Watanabe, as well as their ally, Ion -- as they approached Castle Dracula.