"Koi Dorobō" centers on the life of Aoi, a young woman who has spent years honing her skills as a master thief, specializing in stealing priceless artworks. Her life takes an unexpected turn when she encounters Ren, a talented but struggling artist whose work she initially targets. Instead of stealing from him, Aoi becomes captivated by his passion and creativity, leading her to abandon her criminal lifestyle and seek a new path. The narrative explores Aoi’s internal conflict as she grapples with her past and attempts to redefine her identity, while Ren becomes a pivotal figure in her journey toward redemption.

The story delves into themes of morality, self-discovery, and the transformative power of art. Aoi’s interactions with Ren challenge her to confront the consequences of her actions and the emptiness of her former life. As their relationship deepens, Aoi begins to use her skills for more altruistic purposes, such as recovering stolen art and exposing corrupt figures in the art world. Meanwhile, Ren’s artistic career flourishes, inspired by Aoi’s courage and determination. The dynamic between the two characters evolves from mutual curiosity to a partnership rooted in trust and shared purpose.

Secondary characters, including former associates from Aoi’s criminal past and figures within the art world, add complexity to the narrative. These characters often serve as foils or obstacles, testing Aoi’s resolve and highlighting the challenges of leaving behind a life of crime. The plot balances moments of tension and action with quieter, introspective scenes that explore the emotional growth of the protagonists. Through its exploration of art, morality, and personal transformation, "Koi Dorobō" presents a compelling story of redemption and the pursuit of a meaningful life.