Introduction in the game manual:
In a future not too far from now, the human race has become an endangered species, and the planet is now a wasteland of moldering ruins and lonely ghosts.
Without humans to maintain their creations, all that they had built is slowly begun to rot away. Everything is silently relinquishing itself to the unyielding forces of nature.
For as far back as he could remember Seto lived in an abandoned observatory with a mysterious old man. In the summer of his fifteenth year, the old man peacefully passed away, leaving Seto completely alone.
With the only person he had ever known gone, Seto decided to head out into the world, keeping the old man's last promising words in his heart: You are not alone. With that, he set out to find others like him.
In a land that only responds with the lonely echo of his voice, Seto sets out on a journey in the hopes that there is someone, anyone out there ... waiting for him.