Sei Lori, a teenage student and gunpla creator, hopes to one day outperform his father as the best fighter in a gunpla competition. He is the sole kid of a family that runs a gunpla store, therefore he is incredibly knowledgeable, but because of his subpar piloting abilities, he frequently loses in the first round of competitions.
Throughout the narrative, he encounters Reiji, a weird youngster who goes on to assist him in honing his skills. He offers Sei a diamond and the assurance that he will assist him if he so chooses. They participate in the upcoming competition with Sei's modified GAT-X105B Strike Gundam to face off against the best Gunpla fighters.
