A strange virus, known as the Demon Virus, attacks the human genetic code, transforming people into monsters with demonic powers. One particular monster is terrorising the streets of Tokyo, ripping open young women to devour their livers. A famed psychic holds the secret to the identity and purpose of this monster. Now it is up to two molecular biologists, the self-proclaimed BioHunters Komada and Koshigaya, to reach the psychic and his beautiful daughter before it is too late. The spread of the Demon Virus has to be stopped at all costs...