"Get Backers" centers on the partnership of Ban Mido and Ginji Amano, who operate a retrieval service under the name "Get Backers." The duo specializes in recovering lost or stolen items, no matter how dangerous or impossible the task may seem. Their base of operations is the sprawling, enigmatic Infinity Fortress, a labyrinthine structure filled with powerful factions, supernatural phenomena, and hidden secrets. The series intertwines episodic retrieval missions with a larger, overarching narrative that delves into the characters' pasts and the mysteries of the Infinity Fortress.

Ban Mido is a skilled fighter with the ability to manipulate reality through his "Evil Eye," which creates illusions that can trap or disorient his opponents. Despite his brash and often reckless demeanor, Ban is deeply loyal to his friends and driven by a strong sense of justice. Ginji Amano, on the other hand, possesses the ability to generate and control electricity, earning him the nickname "The Lightning Emperor." His cheerful and easygoing personality contrasts with Ban's intensity, but Ginji harbors a dark past tied to his former leadership of the Volts, a powerful gang within the Infinity Fortress.

The series explores the duo's efforts to reclaim lost items while navigating the complex dynamics of the Infinity Fortress. Their missions often bring them into conflict with rival retrieval teams, criminal organizations, and supernatural entities. As the story progresses, the focus shifts to uncovering the truth about Ginji's past and the origins of the Infinity Fortress, which is revealed to be a living, sentient structure with its own agenda. The narrative also delves into Ban's mysterious background, including his connection to a secretive organization known as the "Brain Trust."

Supporting characters play significant roles in the story, including Hevn, a femme fatale who frequently hires the Get Backers for high-stakes jobs, and Kazuki Fuchoin, a former member of the Volts with a tragic history tied to Ginji. The series balances action, humor, and emotional depth, with each character contributing to the evolving plot. Themes of loyalty, redemption, and the consequences of power are woven throughout the narrative, culminating in a climactic confrontation that ties together the various threads of the story.

The Infinity Fortress serves as both a setting and a central mystery, with its shifting corridors and hidden layers symbolizing the characters' internal struggles and the challenges they face. The series blends supernatural elements with grounded character development, creating a compelling mix of episodic adventures and a cohesive, overarching storyline.