Battle Royale takes place in an alternate timeline, in which Japan is ruled under a Totalitarian Government. Under the guise of a Study Trip, the military government forces a class of students to compete in a game called "Battle Royale," in which the students are then forced to kill each other until there is only one last standing person left in the fight.
Link to Movie:
http://www.youtube.com/watch?v=VwE5-ecnH8gPersonal Opinion: Pretty much like the Japanese Version of Hunger Games, but more superior to it at a side-to-side comparison. Other than that, all movies have something different to offer