MoonPhase (2004)

Paranormal photographer Kouhei stumbles into the arms of Hazuki, a vampire beauty who has waited for years to be freed from a forgotten castle. Unwilling to part with her unwitting hero, the petite vamp follows Kouhei home and starts causing trouble. But domestic disorder is the least of Kouhei’s problems. With dark forces gathering, he’s about to enter a world he can’t begin to comprehend!