In AD 3567, humanity has lost its former civilization and now dwells in desolate wastelands. Their lives are threatened by Gardener, a mysterious unmanned mobile weapon dispatched from the moon. To survive, strong boys and girls become Gardener hunters, earning enough each day to sustain themselves. Despite the collapse, high‑tech, maintenance‑free systems keep the limited functions of cities operational, providing essential support for people’s lives. When a boy visits one of these cities, he discovers the path that will determine his destiny.