Rei and Fuko

Kirisawa Rei and Izumi Fuko are two special agents hunting down a drug syndicate called the 12 Angels operating somewhere in Tokyo. The drug they're distributing, called 'Milk,' isn't your ordinary street product. It has a supernatural edge to it, and the deeper Rei and Fuko dig into the investigation, the darker and more dangerous things get. What starts as a crime thriller setup slowly reveals something much more sinister underneath, which is where the horror elements kick in. This is a 4-episode OVA based on a visual novel by Black-Lilith, so it wastes no time getting to the point — the pacing is tight and the tone stays consistently grim throughout. The animation and character designs have that distinct mid-2000s dark fantasy aesthetic that fans of the era will recognize immediately. If you're familiar with Taimanin Asagi or Bible Black, you already have a sense of the territory this covers — adult content, supernatural horror, and a crime noir atmosphere layered together. It shares some DNA with Night Shift Nurses in terms of its dark institutional settings and explicit tone. This is not a light watch by any stretch. The content is mature and the themes are heavy, so go in knowing what you're signing up for. If that specific blend of supernatural investigation and horror appeals to you, Rei and Fuko delivers a focused story without overstaying its welcome.