it might be a bit extreme but if you want a classic manga... pick up Battle Royale.
Summary: The setting is in Japan and the government developed a new way of educating the "tough kids". They created a program in which random classes from across the country will be selected, only one per year...to enter in a program that has a nationwide broadcast. The rules are simple...eliminate everyone until you're the last living student...however...they only have 3 days to do so before a collar around their necks explodes..