In class C of Hanazono Girl's Middle School, a new student transfers in, shrouded in mystery. Akane, a plain and unassuming girl, is fed up with her controlling clique of friends and has resigned herself to the possibility of the world's destruction. Suddenly, the entire class wakes up to a desolate, eerie school with ominous countdowns ticking away. Each girl is tethered to another, and they must fight to survive a 7-day Battle Royal. To her surprise, the enigmatic transfer student is Akane's partner. As the game commences, friendships deteriorate, optimism fades, and everyone's sanity is pushed to the brink.
