Almost four years after a worldwide plague killed all the male mammals on Earth, the two survivors Yorick Brown and his monkey Esperluette, are in Japan. Yorick and his travelling companions continued Esperluette and the mercenary ninja who took him to the land of the rising Sun, where culture adapted to the disappearance of men in a unique and all-Japanese way. To find the animal whose body probably contains the key to the survival of humanity, Yorick and 355 must travel to Tokyo in a labyrinth made up of yakuza, teenage gangsters and a pop star who became crazy.