Marebito (R)
Dread Central (DVD); IMDb; Rotten Tomatoes; TV Tropes; Wikipedia
streaming sites: Vudu

This came out in 2004, but I didn't see it until 2019. It was written and directed by Takashi Shimizu, who's also responsible for the "Ju-on" franchise, both the Japanese originals and the American remakes (The Grudge). The story is mostly narrated by a freelance cameraman named Masuoka, who at the start of the film happens to record the suicide of a man named Kuroki. He soon becomes obsessed with the look of terror on the face of Kuroki right before he stabbed himself through the eye, and believes that terror was caused by something Kuroki could see that others couldn't. Masuoka later returns to the scene of the suicide, with his video camera, and follows a staircase down into ever-deepening tunnels beneath Tokyo, believing that throughout history, new tunnels had simply been added onto older ones. He soon gets to a level where hardly anyone goes at all, and meets a homeless man, who warns him about things called "Deros," which he says would suck your blood out if they find you. (I found it odd that at one point, the homeless man seemed to respond to something that as far as I could tell, Masuoka was merely thinking, in his narration. The possibility that he was reading Masuoka's mind is not commented upon, but I thought that Masuoka at least seemed slightly surprised.) Anyway, Masuoka continues on his way through the tunnels. He also meets Kuroki, who he assumes to be a ghost. Kuroki talks with him for awhile, though when he finds out that Masuoka had seen him die, he disappears.

Masuoka still continues on his own, until he finds a surreal, subterranean mountain range, which he calls the "Mountains of Madness" (an H.P. Lovecraft reference). He only explores this area for a little while, before he discovers a naked girl who is chained up. He takes her home with him, but she doesn't speak, or seem to have ever had any contact with humans. He starts referring to her as "F." He also finds that she doesn't eat or drink anything... though some time later, he discovers that she will feed on blood. (Animal blood is okay, but she apparently prefers human blood.) Meanwhile, he is contacted by a strange man who has vague warnings for him about the girl. And there's a woman who follows Masuoka sometimes... but I don't want to reveal what she says to him.

And... I don't really want to reveal any more of the plot. I'll just say the whole movie is rather weird, and there are different possible interpretations of at least some of what goes on, but I don't think any of it really made any sort of cohesive sense. There's really no way to be absolutely certain of what the truth is about any of what happens in the movie. (And even if there were, it probably still wouldn't make much sense.) But in any event, it's all pretty disturbing (though not particularly scary).