"Mobile Suit Gundam UC Bande Dessinée" is a manga adaptation of the "Mobile Suit Gundam Unicorn" light novel series, which is set in the Universal Century timeline of the Gundam franchise. The story takes place in U.C. 0096, three years after the events of "Char's Counterattack," and explores the aftermath of the Earth Federation's victory over the Principality of Zeon. The narrative centers on the conflict surrounding Laplace's Box, a mysterious artifact said to hold the key to the future of humanity and the Earth Federation's legitimacy.

The protagonist, Banagher Links, is a seemingly ordinary student living at the space colony Industrial 7. His life changes when he encounters Audrey Burne, a girl seeking to prevent a war over Laplace's Box. Audrey is revealed to be Mineva Lao Zabi, the last surviving member of the Zabi family, who once ruled the Principality of Zeon. Banagher becomes entangled in the conflict after piloting the RX-0 Unicorn Gundam, a powerful mobile suit developed by Anaheim Electronics. The Unicorn Gundam is unique due to its NT-D system, which allows it to interface with Newtype abilities and unlock its full potential.

As the story progresses, Banagher and Audrey are pursued by various factions, including the Earth Federation, the remnants of Zeon known as the Sleeves, and the Vist Foundation, the secretive organization that controls Laplace's Box. The Vist Foundation, led by Syam Vist and his granddaughter Martha, manipulates events to maintain their power, while the Sleeves, led by Full Frontal, seek to use Laplace's Box to reignite the Zeon cause. Full Frontal, a charismatic and enigmatic figure, is often compared to Char Aznable, the legendary Zeon ace pilot.

Throughout the series, Banagher grapples with the moral complexities of war, the nature of Newtypes, and the true purpose of Laplace's Box. His journey is marked by intense battles, alliances with characters like Riddhe Marcenas, an Earth Federation officer with conflicting loyalties, and Marida Cruz, a cyber-Newtype piloting the NZ-666 Kshatriya. Marida's tragic past as a Ple clone adds depth to her character and highlights the ethical dilemmas of genetic engineering and Newtype experimentation.

The narrative builds toward the revelation of Laplace's Box, which contains a document from the Earth Federation's founding era. This document challenges the Federation's authority by revealing that the original charter included provisions for space colonists' rights, which were suppressed after a terrorist attack. The discovery forces characters and factions to confront the legacy of the Universal Century and the future of humanity's relationship with Earth and space.

"Mobile Suit Gundam UC Bande Dessinée" combines political intrigue, philosophical themes, and intense mecha action, staying true to the core elements of the Gundam franchise while expanding on the Universal Century lore. The manga adaptation faithfully captures the essence of the original light novels and anime, offering a detailed exploration of its characters and their struggles within a complex and evolving universe.