During the Tokugawa period in Edo, the samurai, Sensui Kanzaki, and the shinobi, Kenroku Sanada, are being taken to exile by boat. They become caught in a furious storm and are transported forward in time to a devastated Tokyo which is in ruins. They see a man who transforms into a monster before their eyes and then attacks them. They are saved by Kathleen Funada and the old man Maeda who take them to a compound of surviving humans. She and Dr. Yoshinaga explain that the monsters are the result of the virus known as "Gibia" which has infected humans throughout the world.