"Mobile Suit Gundam" is set in a futuristic universe where humanity has colonized space, establishing settlements known as Side colonies. The story begins in the year Universal Century 0079, during a conflict between the Earth Federation and the Principality of Zeon, a breakaway faction seeking independence. The war, known as the One Year War, has devastated both sides, with Zeon employing advanced humanoid weapons called Mobile Suits to gain the upper hand.

The narrative centers on Amuro Ray, a young civilian living in Side 7, who inadvertently becomes the pilot of the RX-78-2 Gundam, a prototype Mobile Suit developed by the Earth Federation. When Zeon forces attack Side 7 to destroy the Gundam, Amuro is forced to defend his home, showcasing his natural aptitude for piloting the advanced machine. Alongside the crew of the Federation warship White Base, including Captain Bright Noa and fellow pilot Sayla Mass, Amuro becomes a key figure in the Federation's efforts to counter Zeon's aggression.

As the war progresses, Amuro's skills as a Mobile Suit pilot grow, but so does his internal struggle with the psychological toll of combat. His development is paralleled by his rivalry with Char Aznable, a skilled Zeon ace pilot known as the "Red Comet." Char, whose true identity and motivations are gradually revealed, becomes a recurring antagonist, embodying the complexities of loyalty and ambition within the conflict. The dynamic between Amuro and Char serves as a central narrative thread, exploring themes of rivalry, identity, and the human cost of war.

The story unfolds across various battles and strategic maneuvers, highlighting the broader political and social implications of the war. Key events include the Federation's efforts to reclaim lost territories, Zeon's internal power struggles, and the moral dilemmas faced by soldiers and civilians alike. The narrative also delves into the lives of supporting characters, such as the White Base crew and Zeon leaders like Gihren Zabi, whose ideologies and decisions shape the course of the conflict.

"Mobile Suit Gundam" is notable for its realistic portrayal of war, emphasizing the impact on individuals and societies rather than glorifying combat. The series introduces a rich universe with detailed world-building, including the socio-political dynamics of space colonization and the technological advancements of Mobile Suits. Through its exploration of war, leadership, and human resilience, the series has become a foundational work in the mecha genre, influencing countless subsequent stories and adaptations.