Darker Than Black: Kuro no Keiyakusha

10 years ago, a force field of unknown origin appeared around Tokyo, which is called "Hell's Gate". A week after its creation, the police discovered the existence of contractors and dolls. While the former are human beings who possess supernatural powers, the dolls are their intermediaries. Unlike contractors, they seem to be generated by a program. As their existences must remain secret from the public, the Fourth Section of Foreign Affairs, which Agent Kirihara Misaki is a part of, ensures that every normal person who comes into contact with a contractor has their memory erased. Following this logic, the police are pursuing a scientist named Shinoda Chiaki. This young woman received an award for her thesis on the physical characteristics of the "Gate" and has been missing for several weeks. Under a false identity, this fugitive will meet Lee, a student who will protect her from contractors and the police. Despite his calm and smiling demeanor, he seems to be one with the mysterious individual who kills contractors, harboring a hatred for them darker than black.