ダンガンロンパ 希望の学園と絶望の高校生 The Animation

Makoto Naegi, an unremarkable student selected by lottery as the Ultimate Lucky Student, arrives at the elite Hope's Peak Academy only to find himself and fifteen classmates sealed inside by the sadistic bear-robot Monokuma. The only way out is to kill a fellow student and avoid being identified in a mandatory class trial: if the killer is caught, they alone are executed; if not, everyone else dies.