"In a world similar to Earth, there are 12 bloodlines, or races. Each bloodline has a champion between the ages of 13 and 17 who is trained as a warrior and is always ready to do battle. When they turn 18, the teen warrior behind them gets promoted. This has been the case for hundreds of years, but no one remembers why — they're always ready for some sort of battle to take place, but it never does. But the tradition continues. And then one day they're called to fight, and all the bloodlines but the winners will be exterminated. They're fighting to be the last race."