A mysterious virus, nicknamed Medusa, is spreading around Japan, turning its victims into stone. Given the impossibility of finding an immediate cure, the government opts for cryopreserving a select group of patients until they come up with a solution. Kasumi, one of the chosen ones, has been asleep for years and her awakening, more than a bed of roses, is a bed of thorns, and happens in the midst of total chaos where monstrous creatures lie in wait all around.