A mysterious transfer student arrives in the third year, class C of Hanazono Girl's Middle School. Akane is a plain and simple girl who was tired of her overbearing friends, and silently thinks that it is okay for the world to be destroyed. However, all the girls of the class wake up to find themselves in a desolate school, with countdown timers. Every girl is tied to another one, and this pair must survive a 7-day Battle Royal. As it turns out, Akane is tied down to the mysterious transfer student. Friendships crumble, hopes are lost, and sanity is tested as the game starts off with a bang!