Xebec

After an advanced race, the Golden Tribe, left to explore other reaches of space, the human race became threatened with extinction. Since the Golden Tribe left, the Silver Tribe has long since been the most dominant race, calling themselves the Golden Tribe's successors. The young princess of the Iron Tribe, Deianeira, searches for the one mentioned in her family's history; the messianic individual that holds the power to save her people. This person she looks for is the only human to have been raised by the Golden Tribe before they departed from the universe. After her ship and crew reaches the ruined planet, Oron, which holds the one she is looking for, they are attacked by the Bronze Tribe. However, right before the attack, they come in contact with a young boy named "Age," who may hold the secrets to their salvation. The manga is told from Iolaus' perspective instead of Age's (like in the anime).

Tatsumiya Island is a peaceful and tranquil island in a corner of Japan. Makabe Kazuki, a young boy on the island, is celebrating the spring of his fifteenth year with his classmate Toomi Maya and others. Blue skies, azure seas, school, and friends... life is the same as usual. But suddenly, the youngsters' daily lives are transformed by the sound of a beautiful voice echoing through the island. "Are you there?" With the appearance of the mysterious life form, Festum, the children are drawn into a battle for the survival of the human race.