The story is set in future Japan, in which the sea level has risen and flooded many of the coastal areas and Mt. Fuji has erupted within living memory. The population has been considerably reduced and political and technological institutions have broken-down. Local communities have become nations and telephone and television no longer exist (although coffee vending machines and streetlights stubbornly continue to work). There are strange new animals and plants (like flying fish and glowing streetlight trees).

The remaining people have adopted a slower-paced, simpler way of life and rely more on each other. Along with the human population are some intelligent, humanoid robots. One of the robots, a female named Alpha, runs a café by the same name in the country outside of what remains of Yokohama. With her trusty motor scooter and her camera she travels around the area making friends with the humans and robots, having new experiences and observing the passage of time.