Tsuyoshi Takaki says in his commentary that he wants people to question what we as humans see as "normal." That's a good summary of this volume - Roue, a girl of about eleven, is the only human in the story, and no one's quite sure how she ended up on Zett's doorstep as a baby in a rocket. Zett, an academic "gear" (the in-world name for robots), takes it upon himself to raise her, but when an insane gear destroys his physical body, Chrome, a strange gear Roue accidentally wakes up, takes over. Chrome is oddly advanced compared to all of the other robots, but once he assigns himself the base program of protecting Roue, we can see him beginning to change and grow in a decidedly human way.

Chrome's ability to decide on his own “base program,” a directive most other gears have installed by humans, is the greatest marker of his advanced state. Although Zett initially seems to take it for granted that Chrome can do such a thing, even he acknowledges that it's at least a little odd to request the first place. It may only be due to Zett's base program as an anthropology professor that gives him the idea to make the suggestion; Zett is a good uncle to Roue (he doesn't want to be called her father) because he finds human behavior so endlessly fascinating. But his more advanced systems also strike other gears that meet Chrome, and the implication seems to be that he was a prototype of a more advanced form of artificial intelligence being studied before World War Three ended, well, everything.

If you're picking up on a few similarities with Isaac Asimov's 1976 novelette Bicentennial Man, that's almost certainly on purpose. Asimov's first law of robotics is explicitly referenced in the story, and in one panel, we have a clear shot of someone reading that very book. Although barely begun in this volume, Chrome's journey mirrors that of Andrew, Asimov's protagonist, right down to the story taking place two hundred years after he was presumably created. In Asimov's book, Andrew grows more and more human as time goes on, and his first human relationship with a young girl he called Little Miss becomes his defining experience. Even the art seems to align with this; when Chrome first comes into the story, he looks like a large, boxy robot, as you'd see in the 1950s, but when he decides that protecting Roue is his base program, he emerges from that form looking remarkably human. Although Takaki's world only appears to have one human, Roue, the parallels are already beginning to show, making this a particularly appealing story to fans of classic science fiction.

This opening volume is largely about setting the scene, but it doesn't feel that way. After we meet Roue, Zett, and Chrome, and Chrome gains the mission of his own volition, he and Roue set out on a journey to find someone who can transfer Zett's memory into a new body. This leads to them encountering more gears – Professor Isaac and his assistant Mary, Kidd the engineer, and later a knight still guarding a specific line in the sand from trespassers. Each character notes Chrome's differences, but more importantly, they contribute to his growing worldview. It would have been effortless for conversations to devolve into info-dumps, but that largely doesn't happen. Instead, we get bits of world history as notes between a few chapters, which gives the feeling of reading a textbook; this is much more appealing than it sounds and allows the story to flow smoothly. Characters like Kidd, who continues to work at the factory he was initially owned by even though all of his human companions are long gone, provide us with a sense of melancholy and how the world used to be, while so-called insane gears, whose software has corrupted over time, help to inform us about how prevalent gears were. It works well to draw us into the story while maintaining that vaguely bittersweet sense of a world long gone that the best post-apocalyptic stories manage.

Takaki's art has some good touches as well. One particularly effective scene features Chrome's thought processes drawn as panels within a full-page outline of his original boxy form. Isaac's “undergoing maintenance” form of a daruma on spider legs is just the right kind of creepy. I initially thought Roue was older than she is because of some inconsistency in how her body is drawn early on. Still, Mary, who has swapped out her original legs for combat ones, provides most of the fanservice. There is a good sense of the world being a vast wasteland from the background art, and each gear is unique enough to show that real thought went into each design.

Heart Gear's premise of an artificial lifeform becoming human through its interactions with a human child is familiar. Asimov very clearly inspired it, and anime fans will also notice similarities to titles like Brigadoon. But that doesn't make it less good, and this is a solid start to what should be a fascinating story.