If you've ever played Mafia, this is that. If not, read below.
There are two groups, typically mafia and village. One of these groups, typically the mafia, is evil. Each night the evil group decides on someone and that someone dies. The next day, everyone from both groups holds a meeting and casts votes, with the por fellow with the greatest number of votes being lynched. The game ends when either side is killed off. There are also special roles which, since this will (probably) be a small game, everyone will get.
Basically, this version goes as follows:
One day, a group of ninjas from assorted schools awake in a strange with no memory of how they got there. Strangely, their instinct and memory tell them that everyone present is their friend, but knowing themselves to be in unfamiliar territory makes it uneasy to trust anyone. Some of them seem content with the situation. However, they view the others as a threat as they feel so happy here they will kill to prevent anyone from leaving. But the thing is, there's seemingly no way to tell whether your cheerful neighbor's helping you or leading you into an ambush. Even if they were your friend, are they now...?
Post here to sign up. I'll send you a PM with your role and what it does. I'll set up a group PM for the evil ninjas to select their target each night and each day's votes will be given here. The results of each day/night I will also put here.