Even if you haven't read the manga (which is easier to find digitally pirated than in print I'm afraid) this story will still be a great read. I found some of the ideas extremely intriguing. In the story, no one knows for certain why the country chooses to conduct these test on a regular basis. Why should the country loose so many of it's youth. There is a presented idea in this story that perhaps a nation is only truly united when it suffers together. There is a shocking and scary truth behind that. Terrifying really.