Night Walker: Mayonaka no Tantei
English title: Nightwalker: The Midnight Detective
Japanese title: Night Walker -真夜中の探偵-
Type: TV
Episodes: 12
Premiered: summer 1998
Source: Visual novel
Genres: Action, Horror, Mystery, Supernatural
Studios: AIC
Producers: Bandai Visual, BeSTACK, Half H.P Studio, Memory-Tech
Duration: 25 min per ep
Rating: R+ - Mild Nudity

Shido Tatsuhiko is not only a private eye... he is also a vampire with no real memory of his past. Joined by Yayoi Matsunaga, a female government agent, Riho Yamazaki, an orphaned teenage girl working as his girl Friday and Guni, a little green imp, Shido must face demonic creatures known as Nightbreed. Meanwhile, Cain, the vampire who made him what he is now, is seeking him...

(Source: ANN)