The Ninja Epidemic

You run right out the door without looking back. There's no way you're going to hang out and wait for the police to show up. And furthermore, there could be more ninjas coming. The prospect of more ninjas showing up to try and kill you is not a good one.

You find yourself in your nieghbors yard still clutching the handle of the butchers knife, when a dozen ninjas surround you, appearing seemingly from nowhere.

They taunt you with thier blade twirling and one of them steps forward from the group. He makes it clear that he is challenging you.

Looks like you have no choice to fight.