The Vampire of the film is known as a kaijin, a Japanese word that means mysterious person and is used for supernatural humans of humanoid monsters.
The idea for Toho to make a vampire film is credited to producer Fumio Tanaka though it wasn't originally meant to start a series. Tanaka misheard Yamamoto mention that he wanted to make a film that would terrify people. However what Yamamoto meant was that he wanted to make a Hitchcock type picture. Tanaka, who was a big Dracula fan, pushed for the vampire project and the two comprised with the unorthodox story that became the final film.
For inspiration, director Yamamoto drew upon the horror manga of Kazuo Umezu as well as the Edgar Allan Poe story "The Facts in the Case of M. Valdemar". Yamamoto also cited Goke, Body Snatcher from Hell as inspiration.
For her vampire makeup, Yukiko Kobayashi wore color contact lenses that gave here eyes their distinct golden appearance. This created a problem as Kobayashi could not properly see through the lenses and would frequently bump into objects while filming.
While this is the first in what is known as the "Bloodthirsty trilogy", none of the films are connected. Their grouping comes from the Japanese titles which all include the word Chiosu, or bloodthirsty.