The children in Bokurano are unlike soldiers on a battle field or cancer patients in hospital beds, but rather a combination of both. Life is no longer a matter of choice, but neither is death meaningless.
That's the setting of Bokurano.
Each character had his or her own past and future, but the setting stripped them of that luxury and allowed each to have only the present under control. The setting becomes an ideal breeding ground for all kinds of weaknesses and strengths.
Bokurano therefore is an anime with fast yet strong character development. That for me is the show's greatest merit.
I wouldn't call Bokurano depressing even though I did cry in a lot of episodes. It's rather enlightening, not in a philosophical way of course.
For me who thinks emotions lead to greater wisdom than knowledge itself can, I think bokurano depicts this truth (or folly) really well.
