Orga's team has been hand-picked to escort Kudelia, the young leader of the Martian independence movement, to Earth for an important meeting. Just as preparations for departure are underway, Gjallarhorn attacks the base in an attempt on Kudelia's life.

The adults of CGS flee in the face of Gjallarhorn's attack, using Mikazuki and the other children as decoys. Gathering the children who have been left behind, Orga decides to fight back against Gjallarhorn, and puts a certain plan into motion.

Thanks to Mikazuki and the Gundam Barbatos, Orga's group has temporarily repulsed Gjallarhorn, though not without many sacrifices. As they are discussing their next move, one of Gjallarhorn's Graze mobile suits again appears at the CGS base.

Kudelia is distressed that so many boys have lost their lives because of her. Mikazuki takes her to the farm run by Biscuit's grandmother, where an unexpected encounter awaits.

Kudelia and Tekkadan finally leave Mars behind them and head for Earth. With a ship waiting for them, they attempt to travel by shuttle to a low-orbital station, but are attacked by Coral's Gjallarhorn forces.

The members of Tekkadan need a guide in order to reach Earth despite Gjallarhorn's surveillance. To gain a powerful backer, they attempt to negotiate with Teiwaz, which is based in the Jupiter Sphere.