Much has been made of the violence in this action thriller from Kinji Fukasaku. The film depicts an annual competition of the future in which, as a lesson to unruly youth, a class of schoolchildren are taken to an island, equipped with various weapons and given just three days to reduce their number to the sole survivor who will then be allowed to rejoin society. Each is fitted with an explosive collar to make sure they play the game - like Survivor but by way of Lord of the Flies. Based on a novel by Koshun Takami, this is a film of contrasting moods, with moments of bleak comedy and grotesque horror being interspersed with genuinely touching insights into teen trauma. It's occasionally ragged, but the characterisation is sharp - particularly Takeshi as a world-weary former teacher who monitors the teenagers' "progress" - and the murderous set pieces are often inspired.

In the future, the Japanese government captures a class of ninth-grade students and forces them to kill each other under the revolutionary "Battle Royale" act.