In 2147 AD, on the doomsday earth covered with gray metal, the robot "Zero" awakened due to the flash of "green" fragments in the database. It disobeys the center's order to "clear out all non-mechanical bodies", secretly cultivates moss and seeds, recruits companions to establish a secret alliance, and sows the fire of life in the steel ruins.
When the center issued a "clearance order for the whole area", Zero and his allies blocked the cultivation area with their bodies, shouting amidst the sound of metal collision: "Green is the origin." Although the machine body was eventually destroyed and the breeding area fell, the "vitality code" uploaded before its death penetrated into the core programs of robots around the world like seeds.
Years later, vines covered abandoned buildings, and robots reclaimed the land side by side with surviving humans. The robot that was once judged as a "malfunction" has already used its rebellion to rewrite the logic of survival for the dead earth - the most powerful program has always been the belief in immortality.
