I have fond memories of seeing this movie soon after moving to New York, and it being one of the first small little movies playing in a tiny little theater with maybe 25 seats, where you really feel like "THIS is why I moved to New York," because you're seeing something that you would be hard-pressed to find anywhere else. This was in 1998, and I recall the usher coming in and asking people, in person, to turn off their cell phones because "the enjoyment of people who have come to see the movie shouldn't be ruined by those who have no inner lives." Now, of course, that theater is closed, this movie is readily available on Netflix, and the question of even having an inner life is completely obsolete.
We open with a man visiting a woman in a mental hospital. Suddenly, he bludgeons her to death. The corpse is later found with an X carved into her neck. We introduce detective Takabe, and learn that there have been three bodies found with the same X marking in two months. The thing is, they've been committed by three different people. The person kills first, then mutilates the body with the X. What could be happening?
We follow Takabe home and learn that he has a wife who is becoming ever-more mentally ill. She always has the empty dryer running. When Takabe turns it off, she appears a moment later and turns it back on. Then we cut to a beach, where a man is wandering around. He meets another guy, asks him where he is, what day it is, then asks him where he is again. He claims not to know his own name or how he got there. This is Mamiya, who will prove to be the "killer." The guy on the beach takes him home, where Mamiya meets his wife. Soon, Mamiya takes out a match, and asks the guy to tell him about himself. Next thing we know, Mamiya is back wandering the streets, and the guy has murdered his wife, and carved an X into her neck.
Takabe meets a psychologist on the case, Sakuma, who becomes his advisor and partner. They interview the man, who says he killed his wife "for no reason." We see Mamiya at a police station, found wandering the streets, not knowing who he is, and when one cop goes out, he lights his lighter, and asks the cop to him Mamiya about himself. When the other cop gets back, Mamiya is gone, and the first cop casually shoots his partner in the head, then carves the X into his neck. The cop is fought in, and has no idea why he killed his partner. They hypnotize him, and find that, with a little suggestion, he enacts the killing again. So we have a case of a "serial killer" who doesn't actually kill himself, but hypnotizes others into killing.
We see his method in action when Mamiya has been taken to a hospital, because he was wandering around not knowing who he is. A female doctor is treating him, and he spills a glass of water on the floor, which she watches creeping across the surface in a hypnotic way. He talks to her quietly, drawing out her career frustrations, and says "all the things that were inside you are now outside." He paints an X on the wall and leaves the room. Later, the doctor wanders into a restroom and kills a complete stranger.
Meanwhile, we've been following Takabe, who is getting pretty frustrated. He has to be stopped from beating up several suspects. Caring for and worrying about his wife is getting to him. He locates Mamiya's apartment, which is filled with books on psychology and Mesmerism (the earliest form of hypnosis) as well as a number of other creepy surprises I'll let you discover for yourself. Then, in a creepy sequence, he's just sitting in the car when suddenly he has an awful feeling. He runs home to find his wife has hung herself. Only--it was a vision. She's fine. And he has to soon realize that his involvement it he case is making HIS OWN murderous impulses come out.
That's all I'm going to tell you. Soon they have brought in Mamiya, and let me tell you, that guy is irritating. He just sits and asks stupid questions in a quiet voice, expressionless, until you just want to murder him--which is exactly the point. As it goes on, Takabe and Sakuma find that their mere involvement with his guy is messing with their minds. Pay careful attention in the final shot, as there is a suggestion that the murderous impulse has become detached from Mamiya himself and taken root, spreading like a virus, through society.
That, basically, is the most interesting thing about this movie: the idea that the impulse to kill can be spread, or triggered in people who are just a touch away from it as it is. This makes it a movie about a sickness in society, which makes it akin to another Japanese movie I really liked, Uzumaki (Spiral), in which people start to see spirals, and become obsessed with them, which becomes a way of commenting on people in a society that are just a touch shy of madness.
Speaking of Japanese social sickness, this director has delivered a number of movies in this vein, including one of my favorites, Pulse, which the isolation created by digital devices turns people into literal ghosts (this was remade into a horrible Kristen Bell movie), as well as Bright Future, a film about smart graduates who can find no work and soon drift into crime. Most recently he changed gears into a family drama, Tokyo Sonata, about an out of work man who still pretends to go to work every day. I'm not sorry I've seen any of them.
In fact, I'd watch some of those others before I got to this one. This is good, extremely well done, but again, the main interest is the concept, and the reality... well, it might not be the most rewarding thing you've ever seen. And it can be pretty irritating at times, and not all that scary or involving. It's good--and it obviously stayed in my mind all these years--but it's not the kind of thing you walk out of saying "Wow, that was GREAT!" Still, if you're interested in Japanese society or want a low-key Japanese detective film, this one is, you know, pretty good.
I guess, but I would watch Pulse first.