"Mobile Suit Gundam 0083: Stardust Memory" is set in the Universal Century timeline, taking place three years after the One Year War between the Earth Federation and the Principality of Zeon. The story begins with the theft of the prototype RX-78GP02A Gundam, codenamed "Physalis," by former Zeon ace pilot Anavel Gato. The Gundam is equipped with a nuclear warhead, and Gato's mission is to reignite the war by delivering a devastating blow to the Earth Federation. The theft occurs at the Federation's Torrington Base in Australia, where rookie pilot Kou Uraki, assigned to the RX-78GP01 Gundam "Zephyranthes," witnesses the event and pursues Gato.

Kou, along with his comrades aboard the carrier ship Albion, is tasked with recovering the stolen Gundam and preventing Gato from executing his plan. The pursuit leads them into space, where tensions escalate as remnants of Zeon, now operating under the banner of the Delaz Fleet, prepare to strike at the heart of the Federation. The conflict intensifies as Kou faces Gato in multiple skirmishes, each encounter highlighting the stark contrast between Kou's inexperience and Gato's seasoned combat skills. Alongside Kou is Nina Purpleton, a civilian engineer and love interest, whose involvement becomes increasingly pivotal as the story progresses.

The narrative delves into the political machinations within the Federation, particularly the rise of the Titans, a faction seeking to suppress Zeon remnants and maintain control through authoritarian measures. The Delaz Fleet's ultimate goal is Operation Stardust, a plan to drop a colony on Earth, crippling the Federation's military and political infrastructure. The climax unfolds as Kou and Gato clash in a final battle, with Kou piloting the upgraded RX-78GP03 Gundam "Dendrobium" against Gato's powerful AMX-002 Neue Ziel. The operation succeeds in part, causing significant destruction, but the Federation's response sets the stage for the rise of the Titans and the events of "Zeta Gundam."

The series explores themes of loyalty, the cost of war, and the moral ambiguity of both sides. Kou's growth as a pilot and his internal struggle with the realities of combat are central to the narrative, while Gato's unwavering dedication to Zeon's ideals presents a compelling antagonist. Supporting characters, such as the pragmatic Captain Synapse and the enigmatic Cima Garahau, add depth to the story, highlighting the complexities of post-war alliances and betrayals. "Mobile Suit Gundam 0083: Stardust Memory" serves as a bridge between the original "Mobile Suit Gundam" and its sequel, "Zeta Gundam," providing critical context for the evolving conflict in the Universal Century timeline.