The year is 152 S.C. The colony planet of Deloyer is in turmoil. In the midst of the upheaval, Crinn Cashim, a boy born into a powerful family on earth, learns of a scheme by his father Donan. Forced to choose between family and friends, Crinn chooses to join the guerilla fighters of the Deloyer rebels. Crinn pilots the newly completed combat armor "Dougram," and joins the Sun Fang Corps. His heroic efforts turn things around for the rebels and their counteroffensive.

However Earth forces Captain Travis, wounded in battle with Dougram, grows a burning passion for revenge. With the lust for vengeance and a burning confidence, he launches a large scale pursuit operation against the Sun Fang corps when at they're most vulnerable, leading to a desperate struggle for survival.

(Source: Shogakukan, translated)