"Medusa," a deadly virus becomes a worldwide epidemic. In order to escape from this deadly virus, a handful of people are chosen to be put into a cold sleep, laying in a capsule hoping for the future cure. Kasumi, a teenage girl is one of the 160 chosen for this procedure, and is guided to a Cold Sleep Capsule Center (CSCC) inside an ancient castle. Understanding that it is hardly possible, Kasumi goes to sleep still anticipating for a reunion with her twin sister Shizuku, who also is infected with the virus. As Kasumi and the others awake, they notice that the CSCC is not as they remembered. Just like the story of "Sleeping Beauty," the castle is covered with thorn, and the awaken are attacked by unknown creatures and monsters! How long were they asleep? Where did the monsters come from? What has happened to the world? Abandoned in the midst of an enigma, the escapade of the seven survivors begins...