Stranger: bakemono ga jiken wo abaku (2016)

Misugi Akira and his companion Maria arrive in Tokyo on a special mission. Akira is there to pick up Ito Kaori, whom he has known since Kaori was a child, so that she can join his and Maria's clan of ageless vampires. But Kaori find her dead, from a local serial killer who fancies himself to be a vampire. When one of the police detectives on the case, Saeki Shoji, starts digging into Kaori's death, the links he finds all seem to lead to Akira and Maria. So now the pair decides that their best course of action is to try and track down the serial killer themselves as soon as possible.