His friends in the various manga and anime incarnations of his story include Beezle, the young Devil of Solitude from Scottish Mythology (part of Celtic Mythology); Chao (or "Katy" in the English anime), a naive little kitty who longs to be a human girl, and to learn magic from a real witch; a spunky little Sphinx (in the second film), and a warm-hearted human girl named Cheri.
Unico's way of bringing happiness to others gets him into trouble with the gods, who believe that only they should have the ability to control others' emotions. The gods send the West Wind to banish Unico to the Hill of Oblivion, but the West Wind takes pity on Unico and declines to follow the gods' commands. The gods are furious when they learn of the West Wind's defiance, and send the Night Wind to capture Unico. To protect Unico from the gods and the Night Wind, the West Wind must continually transport the little unicorn from place to place. Whenever the gods discover Unico's whereabouts, the West Wind appears to spirit him away once again, often without getting to say goodbye to any of the friends he has made - and without any memory of those friends, as Unico's memory is wiped clean each time.
In the 1979 film, Unico was a pet to Psyche, the most beautiful girl in the mortal world and he brought her eternal happiness. But the goddess Venus was jealous and angry at Psyche for being more beautiful than her and kidnaps Unico to make the girl unhappy. Venus orders the West Wind to take Unico away where he would be cursed to wander alone and forget everything he remembers.
Unico appeared in several comic strips by Tezuka, with an ecological message. Tezuka's original manga was serialized in Sanrio's "Ririka" (Lyrica) magazine from 1976 to 1979, and was re-published by Shogakukan in 1984 in a learning magazine for children.
In 1979, the same year the manga ended, Unico made his animated debut in Kuroi Kumo Shiroi Hane (Black Cloud, White Feather), an ecologically-themed pilot film (for a proposed anime television series) which was soon released directly to video. Unico meets a young girl named Chiko who is ill because of the pollution from a nearby factory, and becomes determined to save Chiko's Life in order to cure her by destroying the factory. Unico was voiced in this film by Hiroya Oka.
Although the TV series was not picked up, Unico soon made it to the silver screen in two feature-length anime films produced by Sanrio and Tezuka Productions with animation by Madhouse Studios.
Unico's first movie, titled The Fantastic Adventures of Unico in English and simply Unico in Japan, was released in Japan on March 14, 1981. This musical film, narrated by Iruka, directed by Toshio Hirata, written by Masaki Tsuji, and with animation by Yoshiaki Kawajiri, presents the back story of Unico's banishment and his subsequent travels, as well as his friendships with Beezle (to whom he grants his own horn) and Chao/Katy (to whom he grants the wish of becoming a human girl).
Beezle the Scottish Devil (known as "Akuma-kun," or "Little Devil," in the original version) initially rejects Unico's overtures of friendship, but comes around when he realizes how lonely he really is. After Beezle saves Unico from drowning, the two begin their friendship in earnest, but then the West Wind comes to take Unico away.
The next creature Unico encounters is Chao (Katy), a black-and-white cat who dreams of becoming a witch. Katy and Unico befriend a lonely old woman, whom Katy mistakenly believes is a witch and will teach her some magic as well as transform her into a human girl. When Unico changes Katy into a girl, Katy at first believes that the old woman did it, until Unico proves it was his doing by changing her back into a cat; but Unico, seeing how selfish Katy has become, refuses to change Katy back to a girl, until one day when Katy saves the old woman from drowning. Katy then becomes entranced by a man posing as a lord (Danshaku in Japanese, Baron de Ghost in English). He invites her to his castle, gets her drunk and attempts to seduce her. Unico follows, rescuing Katy (with help from Beezle) after transforming into a majestic white winged unicorn and destroying the demonic Cow Skeleton Monster that the "lord" had transformed into. Afterwards, West Wind comes to take Unico away again, and Katy moves in with the old woman.
This movie includes several songs, most of which were performed by the movie's narrators, singer/songwriter Iruka in the original version and Joan-Carol O'Connell in the English dub; however, Chao/Katy's recurring theme song, Chao no Kuroneko no Uta (The Song of Black Cat Chao), was sung by Chao's voice actresses, Kazuko Sugiyama in the Japanese version and Robin Levenson in the English dub. The movie's other songs include Unico no Teemu (Unico's Theme), Hontou wa Subishikute/Lonely (Beezle/Akuma-kun's image song), and Majo Neko Chao (Witch Cat Chao)/Katy The Kitty Witch, all sung by Iruka or O'Connell. For the U.S. release, all of the songs were dubbed into English along with the spoken dialogue, except for the ending song over the closing credits, which is an instrumental in the English version. Unico was voiced by Katsue Miwa in the original version and Barbara Goodson in the English dub.
Moribi Murano (often miscredited as "Mami Sugino") directed the second movie, titled Maho no Shima e ユニコ 魔法の島へ (To the Magic Island) in Japanese and Unico in the Island of Magic in English, which was released on July 16, 1983, five days before the release of the first Barefoot Gen movie, which used many of the same production staff.
In this film, Unico meets a kind-hearted young girl named Cheri (also spelled "Cherry", voiced by Sumi Shimamoto). Cheri's older brother, Toby (in Japanese, "Torubi", voiced by Shuichi Ikeda), is working for the evil Lord Kuruku (in Japanese, "Kukuruku"), who plans to turn all living creatures, animals and people alike, into unusual zombie-like beings called "Living Puppets" to be his slaves; Toby's job is to change people into Living Puppets and then lure the Living Puppets to Kuruku's island castle in exchange for learning more of Kuruku's magic. His plan is to obey and serve until he learns enough to be the master, but fails to protect Cheri twice. Toby also takes on Melvin the Magnificat ("Yamaneko" in Japanese) - who hates Unico because Unico "intruded" in "his" forest (the forest in which the West Wind left Unico) - as his assistant. After Cheri's parents and neighbors all get turned into Living Puppets, she and Unico team up to stop Kuruku.
Seeking advice from the Trojan Horse, Unico and Cheri learn that Kuruku is a puppet who was mistreated by his owners and discarded. He washed up at the edge of the world - where all unwanted "junk" ends up eventually - and was brought to life with the power of sunlight, determined to take revenge on the human race. With help from the Sphinx's daughter (voiced by Noriko Tsukase; named "Marusu" in Japanese but not given a proper name in the English version), Unico - who realizes that Kuruku is really just a lonely, friendless creature - is able to break Kuruku's spell, but since Kuruku's hatred was the only thing that kept him alive, Kuruku reverts to puppet form, and Cheri keeps him as a toy. Soon afterward, the West Wind finds Unico and spirits him away once again.
As with the first movie, the second movie's ending song (Do-Re-Mi-Fa Lullaby performed by Emiko Shiratori) became an instrumental in the Spanish and English dub. Katsue Miwa in the original version and Barbara Goodson in the English dub reprised their roles as Unico in this film.
Unico had one more anime appearance afterward, in a short film called Saving Our Fragile Earth made for showing at the Tezuka Osamu Animation Theatre at Tezuka Osamu World in Kyoto. This short, like the original pilot, had an ecological theme: Unico and Tsubasa, a talking tree boy, are distressed by the fact that the planet Earth has become polluted and drained of resources to the point of being uninhabitable. With help from the Sphinx and the "Time Fairy" (Astro Boy), the two travel back into the past to try to prevent humans from taking the wrong path and spare the Earth from ecological devastation. Famed voice actress Akiko Yajima provided the voice of Unico in this film.
Unico has a loyal fan following in the English-speaking world as well as in Japan, and this is largely due to the 1981 and 1983 theatrical features, which were dubbed into English and received Stateside exposure through VHS release in the mid-1980s and airings on The Disney Channel (now Disney Channel). However, the original VHS versions of the English releases of both movies are long out of print.
The rights to all Unico manga and anime transferred from Sanrio to Tezuka Productions after Tezuka's death in 1989; unlike Sanrio, Tezuka Productions has no American distribution arm, hence the reason why it took 25 years for the two movies to be licensed for an official North American DVD release.
Discotek Media released both films on DVD, with both the English and Japanese audio tracks in April 2012. The 1979 Unico pilot film had never been released outside Japan at all until 2012, when it was featured as an extra on the "Unico in the Island of Magic" DVD release.
These are also the first Sanrio films to be presented in Bilingual for the 1981 and 1983 theatrical features.
Digital Manga Publishing successfully funded a Kickstarter to publish the manga in full color in English.
Unico makes some cameos in episodes of the Black Jack TV series adapted from the Black Jack manga.
Unico also made an appearance in the Game Boy Advance game Astro Boy: Omega Factor, where he gives Astro Boy the ability to have a warm and tender talk with Dr. Tenma, his father. Unico also appears in the Astro Boy manga in a comic book. In the story, he was Dr. Foola's inspiration for a new robot: a mechanical unicorn.
Unico can also be seen in a brief cameo in Columns GB: Osamu Tezuka Characters for the Game Boy Color.
The Unico films (pilot, Fantastic Adventures, and Island of Magic) were produced by Sanrio, so some of Sanrio's characters such as Hello Kitty, Tuxedo Sam, and the Little Twin Stars make cameo appearances in the films.
On Anime News Network, Shaenon K. Garrity called it "a good-looking manga", saying the "artwork looks like a comic-book version of the prettiest Disney movie never made".