In 2030, people in Japan are turning into different forms of monsters based on their age, sex and race. The illness is named ‘Gibia’ - after being rich in variety like gibier. A pair of samurai and ninja appear in the blighted wasteland of Japan. They both traveled from the early Edo period, fighting together with help from a doctor who tries to find a cure for Gibia. Facing ceaseless attacks from Gibia, and outlaws that attack travelers for food, they start the dangerous journey with enemies all around.