Marebito (2004)

In Tokyo, the freelancer cameraman Takuyoshi Masuoka is obsessed investigating the fear sensation near death. When he shots with his camera a man stabbing himself in the eye in the access to the subway, he seeks what the suicidal might have seen to experiment the same sense of horror the man felt when he died. He finds a passage to the underground of Tokyo where he meets a mysterious naked woman that does not speak and he calls her F. He brings F to his place and he has difficulties to feed her, until he discovers that she drinks blood. Masuika becomes a serial killer draining the blood of his victims to nurse F.