This anime series is set in a world where humans and vampires coexist relatively peacefully in a Special Zone. That peace is threatened by a new breed of vampires; the so-called 'Kowloon Children'. Unlike normal vampires every human, or regular vampire, they bite becomes a Kowloon Child unless killed. The story is centred on an 'Old Blood' vampire named Jiro, known as the 'Silver Blade' and his brother Kotoro who head to Special Zone and are met by Mimiko Katsuragi, a 'compromiser' who's job is to liaise between humans and vampires. Soon Jiro finds himself in the battle against the Kowloon Children... who theoretically shouldn't be able to enter the Special Zone.
If you like vampires and anime this series is worth watching. It nicely follows many usual vampire tropes as well as adding a twist in the form of the Kowloon Children. The fact that these new vampires can't help converting those they feed on mean they aren't inherently evil; just a threat to the peace that still needs eliminating. Jiro is a solid protagonist; skilled but far from unbeatable and Mimiko and Kotaro are good secondary characters. The story provides plenty of action; this is exciting without being overly gory... being a vampire story there is obviously some blood spilt. The animation is good as are the character designs. Overall a pretty good series; I'd recommend it to fans of the genre.
These comments are based on watching the series in Japanese with English subtitles.