Mohiro Kitoh's manga series Bokurano: Ours fits into a few different genres. It's young adult, shonen (literally 'young boy'), mecha (as in 'giant robots'), and one more that seems to be more well-represented in manga than you might expect: the ontological mystery genre. I'll get to what I mean by that in a second; first, let's do a quick plot summary.
One summer in the near future, fifteen kids at a nature camp find a mysterious cave on the beach.
(Remember, kids: read right to left.)
In this cave, naturally enough, is a whole bank of computers...
...and a creepy old dude who offers to play a game with them.
This being a comic from Japan, of course, this game takes the form of giant robots beating each other up.
The story takes a few minor twists which are, if not exactly predictable, are at least unsurprising. The kids and Kokopelli win their first fight, the kids are teleported back home, they decide not to tell anyone about their adventures with the creepy old man in the cave and his giant robot, and the next night the kids are summoned again. Only this time, Kokopelli isn't around; one of the kids is the pilot. And here is where one of Bokurano's major flaws starts to shine, as it were: the series has a lot of characters, and not enough space to do them justice.
Fifteen kids are essentially dumped in the reader's lap all at once in the beginning, and there's only a bare minimum of characterization.
But it doesn't really matter, because here's the big giant shocking twist: after one of the kids pilots the giant robot in battle and wins, that kid then dies.
This pretty clearly sets up the narrative arc for the rest of the series: we get a long, detailed history of one character, only for them to become the next pilot, so we get to see how they perform under fire and what not. So Kodama, the second pilot, who reveres his crass businessman father...
...ends up coldly destroying some buildings while battling his opponent...
...only to accidentally be sent flying and land on a car containing his father.
The first volume—which is all that's been published in the States so far—ends literally a page later, so I have no idea how this particular battle ends, but after reading the Wikipedia page on the series, I can get a pretty good idea of how it all plays out. (Normally, I prefer to read the entirety of a series before doing a review of it—part of the reason that I do so few reviews—but I made an exception in this case.)
I mentioned the 'ontological mystery' genre earlier. What I mean by this is a story where the basic conditions of existence are unclear, where the main characters are not necessarily aware of whether what they experience is real or some sort of hallucination or dream, where they may exist in a liminal state between life and death, and where the truth about their condition may only be revealed very late, if ever, in the series. Bokurano is one of several manga series I've read and anime series I've watched that fit this category: Gantz is another one (which I dislike because of the over-the-top ultra-violence), Haibane Renmei and Red Garden (which are two of my favorite series ever) also fall into this category. In Gantz, the protagonist (who is far from a 'hero') is forced to participate in a 'game' where he must kill bizarre aliens in Tokyo, while his old life and all his friends' memories of him have seemingly disappeared. In Haibane Renmei, all the characters sprout (non-functional) wings and halos, have no memory of their lives before they were 'born' into this world at their current age, and are kept cloistered away from the normal people of the unnamed, vaguely rural European town. And in Red Garden, the four female protagonists are explicitly told that they are dead, that they now inhabit false bodies created to look like their old ones, and must now fight crazed, bestial dog-men on the orders of a mysterious family that may or may not be able to restore them to their original selves. In each of these series, and to a somewhat lesser extent in Bokurano, there are assumptions about the world that have in some way been changed; the characters live in a world with conditions that are somehow different from what they should be, possibly as a result of mysterious and inexplicable forces or beings.
But that's a post for another day. Did I like Bokurano? I guess, but not enthusiastically. The characters are, as I already mentioned, not exactly absorbing, and the story is that 'ontological mystery' crap I blathered about earlier. The art is remarkably bland—simplistic character designs, basic or even nonexistent backgrounds—except for the lovingly detailed giant robots, which each have a unique design.
Is is good? It's better than some I've read, sure. But it's by no means at the top of the young adult heap, or the giant robot heap, or even the ontological mystery heap. It's an okay buy for the young adults—there's some mildly salacious dialogue, a little bit of innuendo, and just enough blood to intrigue those violence-happy boys.