It was supposed to be just a regular daily bus drive to their high school for Watanabe Sheena and her friend Yuki, but when the bus enters a thick fog, the unexpected happens and the bus gets transported to another world that seems prehistoric. With the bus driver gone, the only other passengers on the bus in this mysterious world are all high school girls: Izumi, Ayu, Kyoka, Anna and Jessica. With no cell phone or internet signal, they are completely cutoff from their world. To make things worse, they see hundreds of glowing eyes of predators at night waiting for the girls to make a mistake. How will seven high school girls survive in this treacherous place and get back safely to the real world.