"Now, you will all be playing Mafia here."
"There are 3 mafia members, 1 sheriff, 1 doctor, 7 citizens, AND......The Artificial Intelligence."
A prize for the winner, a death for the loser. 
But unfortunately, this game is indescribably difficult, Because she makes people kill people.

*This novel is an English translation of mafia game, the best-selling book in South Korea.