Tatsumiya Jima is the central island in the middle of a small cluster of islands, in a sleepy backwater of the Japanese isles. Not much happens there, and the island's young people go to school knowing that their lives are likely to remain peaceful and undisturbed -- or so they have been taught... but the truth is different. The fate of mankind is on the line, and Tatsumiya Jima is the last line of defense against a hostile and incomprehensible enemy. At the center of it all, fighting for humanity's continued existence, is the giant robot Fafner, the dragon that guards this final treasure of mankind.