Pluto by Naoki Urasawa & Takashi Nagasaki

If I had to guess who was the most well-known author of manga, I'd go with Osamu Tezuka, perhaps best known as the author of Astro Boy and effectively progenitor of the vast majority of manga available today. His popularity, prolific output, and long career is arguably a major contributor to the large and diverse manga market in Japan. So it's understandable that, for the "birthday" of Astro Boy (Tetsuwan Atom) in 2003, Tezuka Productions would work with a contemporary well-known author—Naoki Urasawa—to produce a commemorative manga themed around Astro Boy.

This is where Pluto comes from: based on a short story by Tezuka, Urasawa and his editor Takashi Nagasaki take the concepts that Tezuka presented in Astro Boy and refashions them into a stand-alone but decidedly more Urasawa-esque narrative. This translates to a darker, more sophisticated take on a world with robots, and plenty of exploration into the concept of artificial intelligence, what it means to be "human-like", and the disastrous consequences that can follow as a result.

Pluto opens with the murder of Mont Blanc, one of the seven Greatest Robots in the World, by a mysterious assailant. One of the remaining Greatest Robots, Europol investigator Gesicht, is sent to investigate the case and quickly discovers that whoever killed Mont Blanc is also after the six remaining Greatest Robots and their inventors. This initially appears to be a revenge plot stemming from their involvement in the 39th Central Asian War, a catastrophic conflict that not-so-subtly resembles the Iraq War. The war ended in wholesale slaughter of vast numbers of robots and seems to have placed all robots on the verge of the next step in the evolution of artificial intelligence: the capacity to feel emotion.

It's very familiar ground for readers of classic science fiction—Tezuka drew heavily from Asimov's robot stories for the Astro Boy mythos, and Asimov's famous First Law of Robotics ("A robot may not injure a human being or, through inaction, allow a human being to come to harm") plays a major role in many developments for the story. It slides easily into the sorts of concept-heavy dialogues familiar to science fiction readers, making it an easy manga to suggest for SF readers reluctant to try manga. At the same time, the Urasawa/Nagasaki team has perfected the suspense narrative through Monster and 20th Century Boys, which keeps the series from getting overly burdened with exposition (the other aspect familiar to SF readers). Too, the characters have a greater visible emotional dimension—even, and perhaps especially, the robotic ones—which makes it an easy SF manga to suggest to those who wouldn't normally tread down the tachyon-particle-beam-paved path of SF.

Pluto ran in a manga serial aimed at an adult audience, so while it does tend to take a more mature approach to storytelling, it also doesn't have the same wistful air of lost youth that other Urasawa/Nagasaki works have, which keeps Pluto an earnest, straightfoward story as opposed to one reliant on nostalgia. In other words, a perfect Tezuka tribute, one that can be enjoyed by young and old alike, whether or not they've heard of Tezuka.