Battle Royale (2000) on Netflix

Plot summary

Under a government act meant to curb juvenile delinquency, an entire junior high school class is selected for a yearly contest called Battle Royale. Shuya Nanahara, still grieving his father's suicide, boards a bus with his classmates and wakes on a remote island. Their former teacher Kitano tells them the rules: three days to kill one another until a single victor remains, explosive collars for disobedience or straying into forbidden zones, and each student receives rations, a map and a random weapon. Noriko Nakagawa, who secretly kept the knife a classmate used on Kitano, is among them. Some students choose to take part; others look for a way to avoid the violence.