||Action, Drama, Mecha, Sci-fi
Long ago, a race of beings known as the Golden Tribe, sent out a telepathic message into the depths of space, to the other races, who were still young. "Come, from the planets you were born on, here into space and join us." Three races answered. The Golden Tribe called them the Silver Tribe (a race that would directly study under the precursors), the Bronze Tribe (a race of sentient insects) and the Heroic Tribe (a race of giants). The Heroic Tribe quickly annihilated themselves save for five individuals, who were subdued by the Golden Tribe and enslaved to the other Tribes.
In time, when the Golden Tribe chose to undertake a journey to another galaxy, there was a last race which answered their call. The fourth race, which took to the stars using their own power, was Humanity. They were named the Iron Tribe.
In the present day, Humanity has been decimated and driven from Earth by the Silver Tribe and their Bronze Tribe slaves. Battle weary and on the run, they receive a new source of hope from their discovery of a surviving Heroic Tribe member, a Nodos, which has taken the form of a young boy called Age. This does not sit well with the Silver Tribe, who redouble their efforts to destroy the upstart Tribe of Iron. They too possess Nodos, four to the Iron Tribe's one.
The story proceeds along parallel lines from this point, following Humanity's search for a new home and for peace, Age's crusade to protect his Human friends and the struggles of the Silver Tribe Nodos as they attempt to understand Age's resistance and their own place in the Golden Tribe's grand designs. [TV Tropes]