Mikazuki belongs to the private security company CGS, at the Martian city of Chryse, which has been hired to escort a girl named Kudelia to Earth. But just as preparations for departure are underway, Gjallarhorn attacks CGS in an attempt on Kudelia's life.
Act OneIn the year Post Disaster 315, Mikazuki Augus fires a gun in an alley way, the recoil makes him fall on his back. His friend, Orga Itsuka (who has blood running down his head and a wound on his left arm) watches. Mikazuki asks Orga what to do next. 8 years later at CGS, Mikazuki asks Orga the same question as Orga slacks off, sleeping beside the a mobile suit. They are discovered by Nadi Yukinojo Kassapa who tells Mika and Orga that the President of the CGS, Maruba Arkay, is calling for them. Despite him telling them not to come into the engine room where the Gundam Barbatos is being kept, Orga and Mika repeatedly go there often because it is warm all year outside.
In the suburbs of the Chryse Autonomous Region, located in the Arbrau Territory of Mars. Maruba briefs Orga and his second-in-command, Biscuit Griffon, who lead the Third Group of CGS on their mission; Kudelia, the daughter of Chryse's representative, and her escort are going to Earth and the Third Group is to guard them. Biscuit knows Kudelia is part of the independence moment and Maruba informs him that her trip to Earth this time is about the Mars Independence too. Maruba claims it is a noble thing. Orga asks why Maruba let them do such a big job. Maruba tells Orga that "The Young Miss" handpicked them herself. Maruba's second-in-command, Haeda Gunnel, tells them that whatever the case, their job is the same as always. He calls them brats and says they should just listen to what he and the heads of CGS say.
Outside, Takaki Uno, Danji Enrei, and Ride Mass are digging up and disposing land mines, claiming it to be bullying. They then see mobile suits firing paintballs at each other in the distance. They are pilots Eugene Sevenstark, Mikazuki Augus and Akihiro Altland, training in a desert-color TK-53 CGS Mobile Worker, a white CGS Mobile Worker and a blue CGS Mobile Worker, respectively. Mikazuki hits a pink Mobile Worker and Eugene's Mobile Worker before dodging shots from Akihiro's Mobile Worker. Takaki Uno stops working for a moment and says he wants to do that one day. Sasai Yankus beats Takaki for working too slowly and yells at his colleague, Todo Mirconen, for not doing his job of disciplining the kids, as Todo yells at the "brats", Sasai says that the "space rats" are all excited. Takaki gets up after his friend asks him if he's alright. In the mess hall, Eugene, Mikazuki and Shino are discussing their next mission. Shino imagines that the young miss must smell so nice but Mikazuki considers her to be a human just like them. Takaki brings water to Eugene, Mikazuki and Shino and Mikazuki asks him about the wound, Takaki brushes it off. Eugene knows that the President picked them over the smooth-talking employees because of their strength and believes that with their next mission, they could overtake the First Corps, alternatively, Orga thinks they were chosen because of the President views them as expendable. Eugene suggests their treatment is a result of Orga's behavior as leader of the Third Group. Biscuit tells Eugene to stop but Eugene tells him to shut up. Believing he's about to fight, Mikazuki pulls hard on Eugene's left ear, threatening to tear it off. Akhiro walks off from the table behind because it is rowdy, as it always is. At the office/home the Chryse Autonomous Government's leader, Norman Bernstein, his daughter, Kudelia tells her mother, Tomomi Bernstein, that she'll be leaving who tells Kudelia not to be rude to the people on Earth. Kudelia had believed that her father was against her action but he has given her such an important task as the mediator with Earth. Tomomi says that it is her habit to take things so negatively and that her father has always worried about her. Afterwards, she walks around her home with her aide Fumitan, Kudelia does not appreciate Tomomi ignoring the truth and wants to see the truth for herself, she confirms to Fumitan that this is the reason she hired CGS as escorts; irregular child soldiers who were born out of Earth Sphere's long rule who embody the problems that currently burden Mars. By interacting with them, Kudelia hopes to at least share some of their pain.
At the Gjallarhorn Martian HQ, a stationary orbital base, Norman meets with Coral Conrad, who commands Gjallarhorn's Martian branch, comments on how beautiful youth and innocence such that the Bernsteins' daughter is seen as the leader of the independence movement, rhetorically asking Norman if it's ironic. Norman, nervously sweating, wipes his face and calls his daughter foolish. Sir Coral says that if foolishness goes that far, it's magnificent, that is why not only Chryse but the "scoundrels" all over Mars support her. He places his haand on a tablet with Kudelia's profile and proclaims that for her to be remembered eternally as a people's icon, they will "help her". Norman, still nervous asks Sir Coral to be "kind". Sir Coral believes Norman is a true coward for selling out his own daughter then asking Sir Coral to be kind and believes he should learn from his daughter. This changes that inspection from Earth into an opportunity. To recieve the support of Nobliss, they need to have her do well. Arriving in the hangar, he tells Orlis Stenja that the mission has been decided.