In the near future, Japan institutes a programme to cope with rising youth crime, by selecting a random class of 14 and15 year-olds and packing them off to an island, where they are given weapons and three days to eliminate each other until a sole survivor remains.
William Golding's Lord Of The Flies has always been a popular set text in schools because it makes young readers wonder what they would do in the same situation. Battle Royale does exactly the same thing, but with even harder choices for its school-uniformed characters.
With a level of violence that restricts it to adult cinemagoers, this will really play when seen by audiences the same age as its characters. The censorious might feel a fantasy like this encourages teen violence, but director Fukasaku Kinji actually does a wonderful job of making the horrors alien and degrading, as a few sympathetic characters rail against the adult system that forces them to act like a conservative's nightmare of rebel youth.
The film deftly establishes its unlikely premise and allows enough glimpses of regular school life to explain why teacher Kitano (played to world-weary perfection by a wry Beat Takeshi) is fed up with his class. Then, the kids are gassed on a bus trip and wake up on an isolated island, where Kitano is empowered to throw a knife into the skull of a girl who talks during a lecture and blow the head off the chief troublemaker to make a point.
Then, for three days, 42 children are on their own, dying in comic-horrific vignettes that often ring uncomfortably true, and showing nobility as often as beastliness. By the time you've worked out who the kids are, most of them have gone, in a succession of surprising, disturbing, touching, horribly funny or deeply upsetting ways. It's impossible to guess which of these neatly-uniformed youngsters is secretly a serial killer, a self-sacrificing hero, a born victim or simply another body count statistic.
Indeed, it's a movie that never lets you settle down, zipping between satire and splatter, offering moments that will make the most hardened viewer cringe and snatches of quiet melancholy that will haunt you for a long time.
Some will be uncomfortable or appalled, and the mix of humour and horror is uneasy, but this isn't a film you'll forget easily. And, seriously, what would you do?