朝日ソノラマ
In January 2011, Asahi Sonorama published the first spinoff light novel series set in the "Vampire Hunter" universe, a prequel series written by Kikuchi titled , illustrated by Ayami Kojima, artist and character designer for the "Castlevania" series of video games. Only two volumes were published, both in hardcover, with a planned third volume on hold since 2013. In May and June 2021 Asahi Shimbun published new paperback and Kindle editions of the two volumes, featuring new cover illustrations by Yoshitaka Amano.