An advertising executive receives a postcard from a friend and uses the image for an advertisement on the spur of the moment. What he doesn't realize is that the image includes a mutant sheep with a star on its back, and that by using this shot, he has accidentally drawn the notice of a guy who threatens him with grave consequences unless he finds the sheep. The anonymous protagonist has an unexpected confrontation with his demons in the isolated highlands of northern Japan, which begins a strange and intricate quest that takes readers from Tokyo to the remote mountains of northern Japan.