The head of the team working on this treatment, Dr. Atsuko Chiba, begins using the machine illegally to help psychiatric patients outside the research facility by assuming her dream world alter-ego, a detective named Paprika.

Atsuko's closest allies are Dr. Toratarō Shima, the chief of the department, and Dr. Kōsaku Tokita, the inventor of the DC Mini.

Paprika counsels a detective named Toshimi Konakawa, who is plagued by a recurring dream regarding an unknown former colleague and a victim in a homicide case he is investigating.

In a meeting with the company chairman, Dr. Seijirō Inui, to discuss the theft of three DC Mini prototypes, Toratarō goes on a nonsensical tirade and jumps through a window, nearly killing himself.

Upon examining Toratarō's dream, which is a parade of random objects, Kōsaku recognizes his assistant, Kei Himuro, which confirms their suspicion that the theft was an inside job.

While investigating Himuro's home, Atsuko ignores the warnings that Paprika gives her, and accidentally slips into a dream space, which, due to her frequent use of the DC Mini, can now affect her constantly.

Seijirō, in a megalomaniacal delirium, returns in the form of a giant humanoid nightmare and threatens to darken the world with his delusions.

A baby emerges from the robotic shell and consumes Seijirō, aging into a fully-grown combination of Atsuko and Paprika as she does so, then fades away, ending the nightmare.

Due to the small scale of release, both Millennium Actress and Tokyo Godfathers had a hard time recouping their investment funds.

[1][15][16] Later, when he met with the author, Yasutaka Tsutsui, and received his permission to make the film, Kon stated that he felt as if he had realized what he had always imagined.

[14] It was initially released in only two theaters, in New York City and Los Angeles, but was gradually expanded to show on up to 37 screens simultaneously.

"[31] Metacritic assigned the film a weighted average score of 81 out of 100 based on 26 critic reviews, indicating "universal acclaim".

[33] Andrez Bergen of Yomiuri Shimbun praised Paprika as the "most mesmerizing animation long-player since Miyazaki's Spirited Away five years ago" (in 2001).

[34] Mick LaSalle of the San Francisco Chronicle gave it a positive review, saying that the film is a "sophisticated work of the imagination" and "challenging and disturbing and uncanny in the ways it captures the nature of dreams".

Nelson later went on to say that Kon "maintains a charming faith in cinema's ability to seduce fearless new (theater) audiences, even one viewer at a time.

"[36] Manohla Dargis of The New York Times said that the film has a "sense of unease about the rapidly changing relationship between our physical selves and our machines."

Dargis praised Kon for his direction, saying that he "shows us the dark side of the imaginative world in Paprika that he himself has perceptively brightened.

"[37] Helen McCarthy in 500 Essential Anime Movies said that Paprika "proves once again that the great science fiction doesn't rely on giant robots and alien worlds".

[38] Conversely, Roger Moore of the Orlando Sentinel gave a negative review, saying: "With a conventional invade-dreams/bend-reality plot, it's a bit of a bore.

"[39] Bruce Westbrook of the Houston Chronicle said the film "is as trippy as a Jefferson Airplane light show" and criticized the characters and the dialogue.

In August 2022, it was reported that Cathy Yan would direct and executive produce a live-action television adaptation for Amazon Studios.

[52][53][54][55] Ciara Wardlow of Film School Rejects argues that Inception was influenced by Paprika based on similarities too numerous to be coincidence, from "the focus on dream sharing technology to Ariadne’s wardrobe to references to Greek mythology, physics-defying hallways, significant dream-elevators, and the choice of having a Japanese businessman (Saito) be the one to hire Cobb and the dream team, among other things".

[53] Patrick Drazen said at least "one scene is a clean and undeniable link: in the climactic dream sequence, when Paprika is trying to escape the chairman and his helper, she defies gravity by running across the wall instead of the floor.

"[52] Julian Rizzo-Smith of IGN claims that "Nolan drew upon famous scenery of Paprika", noting striking similarities such as "the ever-stretching long hallway where Toshimi witnesses a murder, and the visual effect of the dream world shattering like glass.

[56] Steven Boone of Politico said he suspects Paprika "was on Nolan's list of homages", and compares it favourably with Inception, arguing that "Kon confronts his tormented society with visual poetry, not just a remix of tropes and set pieces" and that Paprika "goes deep, where Inception just talks of depth and darkness but, as a screen experience, sticks with glib pyrotechnics".