Nightwalker Midnight Detective is about three main characters, Shido, Riho and Yayoi.
Shido is a vampire who was turned by Cain hundred of years ago. He struggles with his life as a vampire and refuses to harm humans. Instead, he helps rid the human world of the evils of darkness. He ends up meeting a small green winged fairy, Guni. He also runs a small business for the Private Investigator.
Enter Yayoi. She is a twin sister who had struggled with her sister and the evils. As a child her and her sister played with fire, causing Yayoi to have her face burned off. Her sister makes a deal with the evil. Shido intervenes to stop the madness of the sisters. In return for help saving her, she gives herself to Shido for a live feeding. She works as paranormal investigator for the NCI.
Riho is a high school student who volunteers herself to be Shido's secretary. She stops in to visit him before school and after. At first Shido and Yayoi are annoyed by her presence but after a run in with the evil, Riho goes becomes possessed. Shido saves Riho and she learns that he's a vampire. She still comes back even though she knows the truth. Later in the season, Cain captures her to grasp Shido's attention. He hurts her badly to where she will bleed to death. Shido saves her and turns her into a vampire.
In my opinion, this anime is great. It can be confusing but all you have to do is follow it closely. The episodes explain well on background information on the main characters. The only thing that needs fine-tuning is the animation. If it was redone with today's technology, it would be way better. Another thing this series needs is more episodes. Adding maybe another season to it well help explain the ending questions that the series leaves unanswered.moreless