ASTRO BOY paperback series in 2002-2004. Those books were printed in humble black and white on equally modest paper. UNICO (1976-79), by contrast, gets a full-color, slightly oversized, sturdy-spined paperback treatment, and the result is a very handsome package.
* SPOILERS *
The manga version of ASTRO BOY was a series of unconnected, short adventure tales, while KIMBA THE WHITE LION was a single continuous narrative. UNICO falls somewhere between those two stools. The jealous goddess Venus tears the tooth-achingly adorable Unico -- whose special power is to bring happiness and good luck to those who are willing to unconditionally love him -- away from his Greek mistress and orders the West Wind to send the creature across time and space, scrubbing his memory in the process. Unico subsequently has a series of adventures in various time periods and settings -- the American Wild West, pre-Bolshevik Russia, a faceless big city menaced by a factory spewing out poisonous smoke, etc. -- and spreads new hope and newly requited love wherever he goes. In the last of these tales, having been exiled to a desolate spot "at the ends of the Earth" where he'll supposedly get no chance to engage in any more of that pesky bonding and friendship-making, he even manages to befriend a dyspeptic "demon of solitude." Alas, Unico finds no peace even there, as the West Wind returns on the last page to carry him off to "another world." I presume that this meant some sort of extraterrestrial jaunt, but either Tezuka thought better of continuing the picaresque saga or decided that his time would be better spent on other projects. Most of Unico's adventures were adapted into animated form in the early 1980s, accompanied by a few new tales that were not part of the original manga, and these were broadcast on The Disney Channel back in the day.
Sailor Moon) and the wholesale elimination of noses. Since Tezuka was drawing a number of his human characters in a realistic style, while maintaining his policy of reusing character models from the past, the result is an extreme visual mishmash that lacks the coherence of either ASTRO BOY or KIMBA. UNICO also contains multiple references to contemporary pop-culture phenomena such as Star Wars, Close Encounters of the Third Kind, and Pink Lady (well, they were a phenomena in Japan, at least; in the U.S., not so much), all of which the cast members seem familiar with, no matter what time period they call home. The future world of ASTRO BOY and "civilized jungle" of KIMBA seem positively normal compared to this.
Despite its rating as an "all-ages" manga, I don't know that I would suggest using UNICO as an ideal introduction to the works of Tezuka. It has its own share of violence and mayhem (such as a ruthless baron who kills people and animals in his forest for more or less the hell of it) and its WQ (weirdness quotient) is pretty high. ASTRO BOY is probably a better starting point; it raises far more substantial philosophical questions about the nature of technology, progress, and prejudice, and is stoked to the gills with high-octane, robot-busting adventure. As more of an acquired taste, UNICO should probably be set aside until you've tackled some of Tezuka's better-known works.