is a Japanese six-part original video animation series produced by Tatsunoko Production to commemorate the studio's 40th anniversary. Each Karas episode was first televised in Japan as a pay-per-view program from March 25, 2005, to August 3, 2007, before being released onto DVDs. Manga Entertainment compiled and released these episodes as two feature length, direct-to-DVD films for the English market.

Karas tells the story of Yousuke Otoha, a former yakuza, living in a fictional version of Shinjuku, Tokyo populated by humans and yōkai (Japanese spirits). He is one of the titular karas, humans appointed as superpowered agents of the land. Able to transform into a car, an aircraft, and an armored crusader; the skilled swordsman is to stop his corrupt predecessor, Eko, from taking over Tokyo. Supporting characters such as Eko's former henchman, Nue; the yōkai; and Homura, the karas of another city, help Otoha in his quest. A concurrent side story focuses on humans affected by Eko's scheme.

Karas won the Best Original Video at the 2006 Tokyo Anime Award competition, and most reviewers were impressed with the images produced by fusing 2D and 3D art techniques. The story presents themes on the conflicts between cultural traditions and modern society, and the relationship between people. Reviewers, however, found its presentation was too confusing to follow; several of them felt it worsened the show by detracting from the strength of its art.

Plot Ibira initially pictured Karas as a horror story with a vengeance theme. It had a simple plot similar to the manga, Dororo. The protagonist karas is on a quest, slaughtering mikuras to recover the body parts of his murdered lover. Until he recovers all the parts, he assembles them into a katana to kill the mikuras. The final version of Karas was more of a superhero action story, and originally intended for three leading heroes in the same vein as the Japanese period drama, Sanbiki ga Kiru!. The characters Otoha, Nue, and the human detective Kure were the leads but the final version primarily focused on Otoha.Karas Vol. 2 (DVD), Project K. The presentation of Karas differs in several ways from typical anime. The show maintains a serious tone and never indulges in slapstick, exaggerated facial expressions, or super deformed characters. It avoids heavy expositions. Dialogue tends to be short and viewers have to infer what is going on based on very little presented information. The team had left out substantial amounts of information from the show, printing them in a booklet of the final DVD package.

Setting Karas is set in a fictional version of Shinjuku, Tokyo. The show initially showcased larger areas of Tokyo, but the production team felt other animations have featured these areas too many times.Karas Vol. 3 (DVD), Project K. Art designer Hajime Satō created a modern version of the ward infused with a mixture of East Asian cultures. Fictional lettering, resembling Chinese and Hangul characters, fill the billboards and signs. Western gargoyles and Singapore's Merlion statues decorate the streets, and the buildings are modeled on Shinjuku structures of 2003 while blending influences from the Shōwa period.Karas Vol. 2 (説二), Staff Interview — 01 Keiichi Sato, p. 6 This Shinjuku is populated by humans and Japanese folklore spirits, yōkai. The humans have become indifferent to the yōkais presence, and fail to see them as they go about their lives.

The production team envisioned Japanese cities as entities, who require physical agents to execute their will and regulate the activities within them. The concept behind the health of a city is based on traditional Chinese medicine in which the smooth flow of a body's fluids nourishes its internal organs. The team equates yōkai with qi, humans with water, and agents of the city (karas) with blood. They integrated Celtic mythology into their concept for further symbolisms, treating the city as the male (yang); and , the manifestation of its will as female (yin). In contrast, their theory treats the humans and agents as the children of the city and its will, and classifies them as the reproduction system's five major organs. Following the team's vision, the mikuras (evil yōkai) represent the five elements in this system. This idea forms the basis of the relationship between cities and their inhabitants in the show.Karas Vol. 6 (説六), 鴉辭典, pp. 9–10.

Story The main plot centers around the confrontation between Otoha and Eko. After a cold open that announces Eko's plan to remake Tokyo, the story moves ahead three years. Nue arrives in Shinjuku to free his brother from Eko's hold, while Otoha is in a hospital from heavy injuries. The early parts of the show proceed in a "mikura of the week" fashion as Otoha (as a karas) and Nue separately fight against Eko's minions. When the mikuras attack hospitals across the ward to locate Otoha's body, Otoha and Nue work together but when they separate Otoha's Yurine is abducted and he is deprived from the power to turn into a karas. Nue then goes to Eko's base, where Eko kills Yurine and reveals capturing Nue completes the final part of his plan. Meanwhile, Otoha gets into a yakuza fight only to be rescued by Homura, another city's karas. When Eko launches the last stage of his plan and ravages Tokyo with metal tentacles, Otoha ends up among human refugees in a shelter the chief of police had commissioned.

A side story takes place within the main plot, focusing on the humans affected by the ongoing events. Sagisaka Minoru and Narumi Kure are detectives in Shinjuku's Intervention Department who investigate serial murders for supernatural evidence. Mikuras kill and suck the blood of these victims to replenish their strength, but no one except Sagisaka seriously believes in supernatural involvement. Sagisaka is bent on vindicating his daughter, Yoshiko who has been committed to a psychiatric hospital for claiming a mikura committed the mass murder she had survived. Sagisaka's and Kure's investigation brings them to the survivor of another attack, . Director Sato had created her to represent the best qualities of rural migrants looking for better opportunities in the big cities. When Eko starts the last part of his plan; Kure, Hinaru, and the Sagisaka arrive in the shelter Otoha is in.

The chief of police reveals himself as Ushi-oni and starts eating the humans trapped in the shelter. Sagisaka sacrifices himself to push his daughter away from Ushi-oni's attack. Otoha confronts and, in a climatic sequence, his conviction resurrects his Yurine,Karas: The Revelation. Event occurs at 0:52.50. "Homura's Yurine: A Yurine is about to be born. [...] It is happening. Watch closely. The will of the city is born through a human soul, one that is right for that city" which restores Otoha as a karas and he slays Ushi-oni. While karas from other cities observe the showdown between Otoha and Eko, Homura steps in to help Otoha. Otoha carries out Nue's request to kill him and his brother, depriving Eko of his new power source and stopping his entire scheme.Karas: The Revelation. Event occurs at 1:10.30. "Nue: I need you to do me a favor. You're gonna have to kill me with that sword of yours. [...] This is the only way we can stop my younger brother. Please you've got to do it now, or Eko will become even more powerful." Confronting the depowered Eko on equal terms, Otoha finally defeats him. Eko claims Otoha will understand his reasons after 400 years as a karas. Despite defending his human body and Yurine from soldiers ordered by the Deputy Governor to shoot them, Otoha proclaims himself as Tokyo's appointed agent, who will protect all its inhabitants. While Hinaru stays behind in Shinjuku as it is being rebuilt, Kure and Yoshiko have had enough and leave for the countryside.

In a post-credits scene, Eko's boot is found by an unknown character.

Characters

The production team intended Karas to be more than a mere henshin (transforming) hero. Unlike the vengeful protagonist in Mazinger Z, the hero of Karas embodies the spirit of the city, and acts for the city's interest instead of his own. Screenwriter Shin Yoshida sets up a dualism of this idea in the form of two Karas characters; one who believes events are leading to a revolution, and the other viewing them as simply the passing of an era. Manga Entertainment also promoted the hero in Karas as "a cross between a cyberpunk version of the Crow and Batman".

Karas is the title for the city's appointed agents. Capable of transforming into automobiles and aircraft, they are suits of armor animated by human souls infused into them through Yurine's chanting of a Shinto prayer. Director Sato told his animators to enhance the Karas dark nature by drawing their faces in shadows. Fight scenes involving Karas take place mostly in dark settings shrouded with steam or lit with spotlights. Animators touched up film frames by hand, creating an effect different from cel-shaded animation. To make the Karas more menacing, they highlighted the eyes as if light bulbs were shining through them, a technique inspired by the suitmation practice of using light bulbs for the eyes of costumes.Karas Vol. 6 (説六), Interview — Keiichi Sato, p. 14. Producer Takaya Ibira explained the presence of ravens in Tokyo and the Tower of London, inspired him and Sato to model the agents of the city after them. He stated ravens are believed to be omens of good and bad in superstitions, and they always seem to be watching over the cities. This resonated with his view of the raven in the story Noah's Ark, which cursed Noah as it scouted for land. The presence of ravens all over Tokyo led Ibira to notice the same of cats and conceive the Yurines as catgirls.

is the protagonist of Karas. Yoshida wrote out Otoha Yosuke as a character dark in history and actions, breaking the traditional mold of a Japanese hero. He based his idea on his observation of Shinjuku, questioning what sort of a hero a ward exuding an aura of terror and happiness would produce. He portrayed Otoha as the product of incest between his mother and his brother who is the local yakuza boss. Otoha's back-story states him as suffering from congenital insensitivity to pain which lends the character a merciless reputation as his brother's enforcer. The initial concept of Otoha was much darker, casting him as a serial killer who hunts down mikuras to retrieve his lover's body parts.Karas Vol. 6 (説六), 祕初期企畫書, pp. 11–12. This was the first project that worked on.

The main antagonist to Otoha is . His back-story states he was the Karas of Tokyo since the Edo period. In events before the start of the show, Eko turned his back on his duties and started a plan to revitalize the city and its yōkai. He attracted several yōkai to be his cybernetic followers and intended to subjugate the humans. An Oedipus complex forms the basis for his motive. He views Tokyo as a father figure, and his Yurine as a mother figure; and aims to supplant the city's role in this relationship. Eko was a nameless character in the initial draft and known as "Another Karas" with a different appearance, although his prosthetic left leg is retained for the final version.