Masafumi Kobayashi
A middle-aged Occult Detective and documentarian, Kobayashi investigates supernatural mysteries with his cameraman Miyajmima. He is a loving husband to his wife Keiko, but is driven by a need to learn the truth behind his cases, no matter how scary it is. A number of unrelated cases all weave together, putting Kobayashi on a path that ultimately leads to his disappearance, as stated in the film's prologue.
- Always Save the Girl: Spends most of the film trying to save Kana and Marika from Kagutaba.
- Audience Surrogate: Shared with Miyajima, Kobayashi guides the viewers through the mystery and is often scared and spooked on their behalf.
- Be Careful What You Wish For: Kobayashi's motto is that he wants to know the truth, no matter how scary. His latest (and last) case leads him dark a terrifying path of demons, possession, ancient evil, animal mutilation, and cannibalism, and everyone connected to it either dies, disappears, or suffers greatly.
- Cruel and Unusual Death: Keiko is possessed by Kagutaba and sets herself on fire.
- Determinator: Though soft-spoken, kind, and patient, Kobayashi is relentless in his pursuit of the supernatural.
- Don't Go Into the Woods: Goes into the woods where Shimokage used to stand, coming across the old Kagutaba shrine. It's all downhill from there.
- Fat Best Friend: To Miyajima.
- Friend to All Living Things: Very kind and courteous to everyone from children, to weird shut-ins, to mental patients. However, his kindness has limits, breaking into Junko's house in the third act and defends his family from a crazed Hori.
- In-Universe Camera: Takes on the role of a cameraman during the third act.
- Never Found the Body: Kobayashi is reported to have disappeared at the start of the film, and remains missing by the end. May or may not still be alive judging by the video camera sent to his office in his name following his disappearance.
- Occult Detective: Runs a investigation company based in paranormal cases, which appears to be quite stable. Despite looking and dressing like a forty-year old librarian, Kobayashi is an observant, thorough, and skilled detective. He specialises in ghost encounters primarily and supernatural phenomena.
- Papa Wolf: To Kana and Junko's unnamed son.
- Paranormal Investigation: His profession and the focus of his documentaries.
- Parental Substitute: For Junko's son. That doesn't go so well.
- The Stoic: Remains mostly calm and composed around spooky things, but will naturally be frightened if things become too terrifying.
Miyajima
Kobayashi's friend and cameraman.
- Audience Surrogate: Serves as the eyes of the audience throughout the film, a majority of the movie shown through his camera.
- Camera Abuse: Miyajima is quite stable with his camera, even when the characters are traversing the scariest moments of the movie. It glitches for the first time when Hori freaks out upon asking what Kagutaba is, creating an Ominous Visual Glitch showing a collection of Kagutaba masks.
- Flat Character: We never really get to know Miyajima as a person since he is offscreen most of the time.
- In-Universe Camera: Kobayashi's cameraman.
- Small Role, Big Impact: Subverted, since he is the film's cameraman and main point of view.
- The Voice: Rarely makes a physical appearance, since he is carrying the camera, and we only hear him make the occasional comment. Even when he is on screen, we never actually see his face since it is just out of shot.
Marika Matsumoto
A television actress who encounters Kagutaba during a broadcasted ghost hunt, Marika calls upon Kobayashi for help when she begins sleepwaking and performing strange things at night.
- As Himself: Marika is played by Marika Matsumoto. The real Matsumoto was mostly a voice actor rather than a TV actor at the time of the film, but she's still essentially playing herself.
- Break the Cutie: Marika is a sweet-natured and kind woman, but her involvement with Kagutaba causes problems for her in the haunting department.
- Damsel in Distress: Periodically possessed by Kagutaba. Never physically in danger, nor does she get kidnapped, but her on-and-off possession turns her life upside-down.
- Demonic Possession: A non-standard example. Marika isn't directly possessed by Kagutaba, but influenced by him, having a couple of psychic attacks, sleepwalks to fashion herself nooses, and occasionally lets out a demonic groan. Also attracts suicidal pigeons. It turns out that Kagutaba may either be trying to use her as medium, or to be a sacrifice in his resurrection. Kobayashi helps her be free of Kabutaga's influence by completing the pacifying ritual. She is attacked one more time when Kobayashi and Hori stumble across the shrine, but is freed for good.
- Psychic Radar: Marika can sense ghosts and the presence of others, but a ghost hunt near Kagutaba's shrine attracts the demon's attention.
- Sleepwalking: Marika begins to sleepwalk after her initial haunting, finding herself drawing weird imagery and crafting looped nooses from yarn and wires. They are later revealed to be related to Kagutaba and invoked by suicidal worshippers to pay tribute to him. This includes Marika's neighbour Midori.
Kagutaba
The malevolent entity at the root of all problems in the film.
- Animal Motifs: Pigeons. People possessed by Kagutaba seem to attract pigeons, and are shown to build makeshift totems out of them.
- Big Bad: The movie's biggest antagonistic force.
- Cult Colony: The main entity worshipped/feared by the (now underwater) cult of the village of Shimokage.
- Demonic Possession: Does this to quite a few people, seemingly multiple at a time, even.
- Eldritch Abomination: It's never sufficiently explained what the Kagutaba actually is or where it came from, its mere presence (which is felt everywhere) drives people to do bizarre things and it has a habit of mind-controlling people to commit suicide. Kagutaba spends the film controlling people to summon itself into our world, but if there is any purpose behind its actions beyond that, it's utterly incomprehensible - it never seems to be an actively malicious character but more a generally harmful force that cares little to not at all about the people it destroys, and doesn't seem to pursue anything more. The first thing established about Kagutaba is that no one in the modern world knows what it is, and that those who knew about it in older times summoned it to kill people - though it's completely ambiguous as to whether or not they forced it to do so, or if it would have done these things anyway.
- Evil Is Not a Toy: At first, its cultists used Kagutaba for their own means, before it quickly showed itself to be outside of their control. They then became devoted to making sure to keep it sedated.
- Humanoid Abomination: When it acquires a human body. At first it's just an eerily silent and non-responsive boy, before laying to rest any doubts about its true nature in spectacular fashion...
- Would Hurt a Child: Its machinations result in many, many children being killed, sometimes only for being neighbors with the people involved with it.
