A high schooler becomes a mobile suit pilot not through destiny or military conscription, but through an illegal street sport where winning means everything because losing costs you visibility in a world that wants you invisible. The GQuuuuuuX isn't a legend waiting to be discovered, it's a weapon you fight in because the alternative is staying small. When an actual war refugee's Gundam crashes into that underground scene, the gap between playing at survival and actually surviving becomes the only question that matters.

Amate Yuzuriha is a high school student living a peaceful life on a space colony with her mother, though she longs for something more exciting. After meeting Nyaan, a war refugee, she is pulled into Clan Battle, an illegal sport of mobile suit duels. Taking the entry name "Machu," she fights day after day at the controls of the GQuuuuuuX. Then an unidentified Gundam appears before her, chased by both the space force and the police, and its pilot is a boy named Shuji. Machu teams up with him in a string of escalating clan battles as signs of a larger conflict gather. The Gundam action drama is set six years after the One Year War.