During what seems like a harmless school excursion, students from Shiroiwa Junior High School find themselves drugged and transported to Okishima Island School. Here, on the desolate Okishima Island, they discover they are part of a chilling event known as the Program. Every year, since as far back as 1947, 42 third-year students engage in a brutal fight to the death until only one victor remains. Tracked by neck collars equipped with surveillance and explosive devices, any attempt to defy the Program's rules leads to fatal consequences. As the clock ticks, the students must navigate this deadly game or face a collective demise if no winner emerges within 24 hours.