A new type of virus makes 'GIMP', the dead that eats human flesh, which results in leading 99 percent of human in the world ruined. In a school surrounded by fences against Gimps, seven girls lead school lives. The girls are the hope for the human; Nonoka, Moe, Emiri, Nagi, Akari, Karin and Miyu. They are only taught how to fight against Gimps, not knowing the world outside of the school and other than their teachers. However, the nightmare Momoka had have gradually been changing their lives. One day, Moe gets bitten by a Gimp during their training. This incident triggers Nonoka to have distrust for the school. Confliction with the school principal. In the end of the battle, finally, the girls will learn the fearful truth...! nagi and her big guns...