Water now blankets almost the entire surface of Mars, leaving humanity to thrive aboard vast orbital cities that drift across the planet"s endless seas. Life for those who remain on the red world is harsh: the economy has collapsed, jobs are scarce, and nourishment costs a fortune. Gram and his companions strive to survive, yet opportunities keep evaporating. Some have turned to piracy as a revolt against the corrupt regime; among them are the infamous raiders of the Ship of Aurora. In response, Earth"s governing authority—who oversee Mars—has sent a fresh squad of combat pilots to neutralize the threat. Equipped with specialized mech units known as Round Bucklers, they aim to secure Martian waters for all. Coincidentally, Gram finds himself pursued by the most notorious marauders on Mars, and surprisingly, he begins to grow fond of them. Their shared hardships forge unlikely alliances, blurring the line between foe and friend, while hope flickers.