"Ai no Kusabi" is a science fiction series set in the dystopian world of Amoi, a society governed by a strict class system. The narrative explores themes of power, control, and forbidden relationships within this hierarchical structure. The story centers on Riki, a street-smart "mongrel" from the slums of Ceres, and Iason Mink, a high-ranking Blondie—a genetically engineered elite who rules over the city of Tanagura. Their relationship begins as a master-pet dynamic, with Iason claiming Riki as his pet, a status symbol among the Blondies. However, their bond evolves into a complex and emotionally charged connection that defies societal norms.

Riki, a former leader of the Bison gang, struggles with his identity and pride as he navigates his subservient role under Iason. His defiance and resilience make him a compelling figure, while Iason's cold exterior gradually reveals deeper layers of vulnerability and obsession. The tension between their social standings and personal desires drives much of the narrative, highlighting the oppressive nature of Amoi's class system. Supporting characters, such as Guy, Riki's loyal friend and former gang member, and Raoul, another Blondie who questions Iason's actions, add further depth to the story.

The plot unfolds through a series of flashbacks and present-day events, revealing the progression of Riki and Iason's relationship and the consequences of their choices. The world-building emphasizes the stark divide between the privileged Blondies and the marginalized lower classes, with Tanagura's advanced technology and Ceres' impoverished streets serving as contrasting backdrops. Themes of love, loyalty, and rebellion are interwoven with the characters' struggles against societal constraints, creating a narrative that is both emotionally intense and thought-provoking.

The series is known for its mature and often dark tone, addressing themes of power dynamics, exploitation, and the human condition. Its exploration of forbidden love within an oppressive system has made it a notable work in the science fiction and yaoi genres. The story's focus on character development and its intricate portrayal of a dystopian society contribute to its enduring appeal.