Kairo, also known as Pulse (or sometimes Circuit) in English, is a 2001 Japanese horror film by Kiyoshi Kurosawa.
Set during the computer boom and the birth of the internet in the early 2000s, the film features two protagonists: Michi Kudo, a young worker who just moved to Tokyo, who finds herself plagued by strange and frightening events that seem somehow connected to computers and the internet after one of her coworkers kills himself; and Ryosuke Kawashima, a college student who has noticed his own computer exhibiting strange behavior and showing him videoes of people alone in dark rooms, acting bizarrely.
As disappearances, suicides, disasters, and ghost sightings begin to pile up around them, Michi and Ryosuke struggle to find an explanation for what is happening and if it's even possible to stop it.
An American remake titled Pulse (no relation to the 1988 horror film of the same name) was released in 2006, starring Kristen Bell, Ian Somerhalder, and Christina Milian, and was followed by two sequels, both released in 2008. Kurosawa himself later adapted the script into a novel.
Not to be confused with the 2012 Puzzle Game Kairo.
The Japanese original contains examples of:
- All There in the Manual: Kawashima is only ever referred to by surname in the movie, and his first name is only revealed in the credits and supplemental material.
- Apocalypse How: By the end of the film, we learn that events similar to those in Tokyo are taking place all over the world, implying at least a Class 2 disaster.
- Arbitrary Skepticism: Kawashima declares that he'll never believe in ghosts even if he meets one and refuses to give in to the despair that seems to be overtaking everyone else. Until he does meet a ghost himself.
- Downer Ending: When all is said and done, Tokyo and likely most or all of Japan are in ruins, we've learned that similar things are happening all over the world, Ryosuke is dead or worse, and Michi is the only named character who is for sure still alive, and her eventual fate is uncertain.
- Driven to Suicide: Michi's coworker Taguchi, followed by others throughout the film.
- Dwindling Party: One by one, the characters that we meet begin to die or disappear until only Ryosuke and Michi are left.
- Go Mad from the Isolation: A variation where nobody is physically isolated from each other, but technology and loneliness have prevented them from forming real connections with other people. Harue posits that everyone in the world is born alone, and that they'll be forever alone in the afterlife as well. The ghost Kawashima encounters at the end seems to confirm the latter.
- Haunted Technology: Pretty much every computer, disk, or any other technology is most likely infested with ghosts.
- Madness Mantra: "Help me... help me..."
- Mind Screw: Even if you understand the basic premise of what is happening, the movie is confusing and keeps the viewer off-balance.
- New Media Are Evil / New Technology Is Evil: Though it's not the computers or internet themselves that are evil, it's that they're allowing ghosts to invade the living.
- Nothing Is Scarier: Long stretches of the film are quiet, slow, and serve only to ramp up the tension. Even when things do start to pick up, the viewer isn't left with many answers.
- Sealed Evil in a Can: Sealing up doors with red tape when someone within has killed themselves or vanished seems to keep the ghosts contained. The problem is that other people keep opening the doors anyway.
- There Are No Therapists: Nor police or any other kind of helpful authority figure that you'd think the characters could notify of the troubling behavior taking place around them. This plays into the movie's themes of isolation and helplessness, however.
- Wham Line: When Ryosuke is cornered by a ghost while searching for fuel, it gives him the following lines that hint at why the ghosts are so intent on attacking humankind before driving him over the Despair Event Horizon:Ghost: "Forever... Death was eternal loneliness.
Ghost: "I am real..."
The American remake and its sequels contain the following tropes:
- Digital Piracy Is Evil: In the first film, Stone (Rick Gonzalez), offers his female friends some movies that are yet to be released.
- Five-Token Band: The first film features as its main characters a blonde American girl (Mattie) and her white boyfriend (Josh), their white friend, a Latina Best Friend (Isabella "Izzy" Fuentes), and their Latino friend (Stone).
- Hanging Around: Mattie (Kristen Bell) pays a visit to her boyfriend's apartment. In his suicidal state, he excuses himself and hangs himself in the bedroom.
- There Are No Therapists: Averted, in a way. Mattie and Izzy are Psychology students. After her boyfriend dies, Mattie goes to a professional, but he cannot be of much help, since this is a horror movie about a curse that spreads digitally.
- Two-Part Trilogy: Although the first film, Pulse (2006), is a standalone, its sequels, both released in 2008, veer into their own storyline, with Pulse 3 following on plot threads set by Pulse 2: Afterlife.
- The Worsening Curse Mark: In the first movie, after an encounter with the digital curse, Josh and Stone begin to show dark blotches on their skin that grow as time passes.
