Here is a plot idea from another forum:
A mysterious group of rogues, unknown to anyone, has gone to each and every hidden village and has begun to place headbands from opposing villages in each one. It is unknown what there goal is, but it is believed they want a major war between all villages.
However, one day, during a mission, one of the rogues is caught and the plan is revealed as the war. It is up to 2 shinobi from each village to group together and fight all the rogues off before there plans are complete.
Discuss this in anyway and think of ways to fix it and make it 'better'