The world following an apocalypse is a theme that never goes out of style in science fiction, even if some points in history make it timelier than others. Most visions of a world destroyed take a dark turn, showing the dregs of humanity either learning to live in a state far below where we are now or focusing on the struggles for survival that the few remaining humans must take on. Girls' Last Tour is a little different. Instead of looking at things from the darkest possible angle, the story instead gives us the almost carefree adventures of Yuuri and Chito, two teenage girls in their mini motorbike tank, as they explore what remains of a giant stratified city some time in the distant future.

Just when that future is, we don't know. We know that digital cameras were a regular thing before the apocalypse, because in the previous volume, the girls acquired one, and this time they set out to document parts of their journey. Unlike with the diary, which Chi occasionally records their encounters in, Yu has charge of the camera, and with her more childlike disposition, she's more interested in capturing weird images left by a religious cult than in actually preserving evidence of where they've been. That photos are so far removed from the girls' experience that they don't see them in the same way as a diary is an interesting statement of how far the world has fallen – while most of the usable tech that seems to have survived looks to date to the mid-twentieth century (at least in terms of when it was initially designed), more “frivolous” pieces of technology, like cameras, has fallen beyond the scope of what the average person has experienced. It's interesting to the girls, but it isn't going to feed or shelter them, making it a novelty rather than a truly useful thing.

What's really important to Chi and Yu is food, shelter, and light. They are drawn to a temple because it remains illuminated at night, and when they find an old apartment block, the fact that it has a roof, running water, and electricity is what's most appealing about it. Their dreams, essentially, are simple: bookshelves, a pantry, and a bunk bed are what they yearn for the most. What's interesting is that they could have managed to establish all of that in the abandoned apartment, making trips to forage, but the idea of “home” is such a dream that they can't even fathom making it work. They're futuristic Travelers, with a tank instead of a caravan, and “home” turns out to not truly be in their vocabulary.

That's an idea that's particularly interesting when they meet up with a slightly older woman, Ishii, in the last quarter of the volume. Ishii has been camped out at an old Air Force base, compiling schematics to create her own airplane. The base housed a collection from the Wright brothers' original blueprints to what look like a step beyond modern fighter jets, and Ishii has been studying and tweaking designs based on what she can find in the old hangars. This is the second major indication that we've had that there was a substantial military presence in this city at one time, and this base's collection of schematics implies that perhaps there was a preservation component to its mission – as if the old people saw the end coming and took steps to ensure that history would survive. The fact that a “food production plant” is also nearby, and was still somewhat stocked when Ishii moved in, also indicates that there were steps taken to prevent the very world the characters now live in.

The question then becomes “what went wrong?” To a degree, that's actually less important that following Yu and Chi as they journey through their not-quite-wasteland. While it would be interesting to find out, that's not really a factor for the girls – they're just surviving as best they can. When Ishii speaks of another city beyond the sea, Chi and Yu are surprised – but they express no real interest in going to find it. While this might smack of laziness to us, and it certainly is an unusual reaction in an adventure-formatted story, it also says a lot about the series' world: curiosity is fine and probably good, but at the end of the day, it's more important to focus on making it to tomorrow.

Despite all of this, Girls' Last Tour's second volume is no more depressing than the first one. Melancholy, yes, in terms of its vast expanses of empty cityscape and the implications that come with it, but not actually sad. Yu and Chi are happy, and their journey is a quiet one for us to follow. The plot sweeps readers along like a gentle current, making it easy for us to just drift along with the girls. While there might be something alarming in the use of the word “last” in the title, this is probably the most peaceful post-apocalyptic story out there. Whether we're in Tokyo or New York or Istanbul, it isn't the world we know – or even one that the girls really understand. But it is one worth exploring on a day when you want to let the silence of the tale to wrap you up as Chi and Yu roll endlessly on.