Ghost Hound

15-year old Tarou lives in the quiet, remote mountain town of Suiten at his parents' sake brewery. He had a traumatizing experience when he and his older sister were kidnapped for ransom 11 years before. His sister died during that event and Tarou now suffers from narcolepsy and recurring nightmares in which he sees her lying on a bed, yet cannot hear her voice nor remember the face of their kidnapper. He also has out-of-body experiences, in which he tries to meet his sister again. His mother has also been deeply affected by the events, prompting her to seek psychiatric help with some limited success.

Tarou discovers two other boys, Masayuki and Makoto, who like him suffered trauma in their past and who can project their astral bodies into the "Unseen World". He also meets Miyako, a young Miko at a local shrine who appears to have great spiritual powers, and thinks she might be able to help him on his quest to find out what happened to him and his sister. Add to this the arrival of an eccentric therapist who wants to help Tarou with his problems, and you soon get a complicated story in which seemingly unrelated events appear to have a deeper connection, with a central role for the mysterious biological laboratory located in the mountains near the town.

Ghost Hound is a 22-episode anime series that aired in 2007 and created by Production I.G and Shirow Masamune, who were also responsible for the Ghost in the Shell series. It is part fairytale, part detective thriller, and with a great amount of (faux) science thrown in for good measure. The series is devoid of typical anime-fare like slapstick or Super-Deformed artwork, with only mild amounts of Fan Service--which is primarily concentrated on one character.

The ending might be a bit anticlimactic, but lovers of thought-provoking anime in the line of Serial Experiments Lain or Boogiepop Phantom may find the series thoroughly enjoyable.

Tropes used in Ghost Hound include:

Abandoned Hospital: The creepy old building in the dam where Mizuka died.
Animal Testing: Outori has some specially prepared rats in a maze.
Artificial Human: Dai-Nippon Bio's secret project is a series of these (called Hopeful Monsters) for organ harvesting.
Bad Dreams: A major plot point for Tarou, who records them on a tape recorder.
Bishonen: The entire male cast for the most part. Especially Tarou who is downright Moe.
Connect the Deaths
Contemplate Our Navels: A good 50% of the screentime.
Crossdresser: Tarou at one point dresses up as a Miko in an attempt to rescue Miyako.
Crowning Moment of Funny: "You're in my head!"
Dead Little Sister: Inverted with Mizuka, who is a Dead Big Sister, but plays a similar part.
Driven to Suicide: Makoto's dad, as well as his mom and her lover, though she survived. This also happened to a student Masayuki used to bully, traumatizing him.
Easy Amnesia: Tarou has this due to head trauma.
Evil Matriarch: Makoto's grandmother.
Generation Xerox: Masayuki and his dad both fall for Outori. The boys vow, however, not to drift apart and stay friends, unlike their parents.
Hello, Nurse!: Outori, she's a real headturner throughout the whole series.
Invisible to Normals: The spirit layer.
Jerkass: Makoto. May or not have a Hidden Heart of Gold, and is certainly a Jerkass Woobie.
Jigsaw Puzzle Plot
Miko: Miyako
Mind Control Eyes
Mind Screw: The plot takes a few odd turns here and there. The chicken ghosts, for instance.
Moe
Ms. Fanservice: Outori, who is the show's sole source of some moderate display of boobs & legs.
Mundane Fantastic
New Transfer Student: Masayuki
Nightmare Fuel: The spirits are often downright spooky. The ambient music and sound effects are spectacularly creepy.
No Social Skills: Masayuki simply does not know the meaning of the word 'tact.'
Oracular Urchin: Miyako
Ordinary High School Student: Well, apart from the ability to project his astral body into the spiritual place.
Organ Theft: Taro and Mizuka were kidnapped by a member of a child organ trafficking ring, though circumstances made the kidnapper demand a ransom instead.
Our Ghosts Are Different
Perpetual Frowner: Makoto
Psychic Powers
Red Herring: Many viewers thought the creepy-looking psychologist that Taro visits had some kind of sinister agenda. Turns out he's just as much a victim of all the weird paranormal shenanigans as everyone else.
Religion Is Magic
Religion of Evil: The Ogami Sect.
Scary Shiny Glasses: Atsushi Hirata and Reika Outori. Hirata is more scary.
Scenery Porn: specially in dreams sequences
Science Is Bad: Definitely elements of this, although it also attempts to half-justify some of the weirdness with scientific concepts -- or things that sound like scientific concepts. See Techno Babble, below.
She's Got Legs: Outori.
Shout-Out: One of the characters in the show names his astral projection self Snark, after Lewis Carrol's The Hunting Of The Snark. In fact, the title of the episode in which he makes his first appearance ('For The Snark Was A Boojum, You See') is a quote from the story.
Spirit World: The Unseen World.
Split Personality: Miyako, sort of.
Staircase Tumble: The endless set of stairs outside Miyako's father's shrine are dangerous as hell.
Stepford Smiler: Most characters turn out to be thisonce their secrets are revealed.
Suspiciously Similar Substitute: Miyako looks eerily similar to Mizuka, which eventually leads Taro to believe that she's her reincarnation.
Techno Babble: The show is rife with explanations from psychology, neurology and quantum mechanics, usually linked in an arbitrary manner. Sometimes the characters give reasonably accurate descriptions of these concepts, but draw ridiculous conclusions from them, especially in Miyako's next episode previews.
There Are No Therapists: Averted, since one of the more important characters is a therapist, who actually helps some people. How about that.
Town with a Dark Secret: Suiten has a lot of secrets you don't wanna know about.
True Companions: Boys, at the end.
Uncanny Valley: Most of the spirits fall into this. Especially the one shown in the abandoned building in episode 4.
- The "hopeful monsters" are insanely creepy.
The Unintelligible: In the 'previously on' segments, everybody's dialogue is reduced to creepy incomprehensible gibberish. Until a possessed Miyako manages to proclaim quite clearly that she's 'The Lord of One Word.'
Voluntary Shapeshifting: The kids eventually learn how to change the shape of their astral projection selves, changing from the bobble-head things to their normal selves (and Makoto and Taro learn how to transform into ghost hounds.
Weirdness Magnet: The mountain is the super-conductive gigawatt neodymium type, and it seems to have rubbed off on Tarou.
What Happened to the Mouse?: Remember Chiyo? Miyako's friend who sold her out to the cult? The one who was repentant and left crying at Makoto's house in the end? The house that got destroyed in a landslide?
- Also , Furusawa, the lab assistant, the dude who threw the bioids into the dam. Was he caught? What were his motives? Then, there's Kabata, the lady who worked for the Ogami family. Did she get arrested or something for forcing a 6th Grader to lead the sect? Isn't there a law against that sort of thing?
Writer on Board: Masayuki, Tarou, and Miyako's dad are discussing humans and nature, and Miyako's dad mentions that sometimes spirits will take revenge if abused by humanity. Masayuki says, "oh, like global warming!" and Miyako's dad launches into a dissertation on how there's no evidence that global warming is manmade (using the argument that the hypothesis was formed to support nuclear energy) and that humans have been good for biodiversity (using the Tokyo plain as an example).
You Gotta Have Blue Hair: Furusawa, the lab assistant.
You Look Like You've Seen a Ghost: Even happens to the main characters themselves.