"Abenobashi Mahô Shôtengai" is a surreal and genre-blending series that combines comedy, fantasy, and science fiction elements. The narrative centers on two childhood friends, Sasshi Imamiya and Arumi Asahina, who live in the Abenobashi shopping district of Osaka. After a mysterious incident involving a falling air conditioner, the duo finds themselves transported to alternate versions of their familiar shopping arcade, each reflecting a different genre or theme, such as fantasy, sci-fi, or post-apocalyptic worlds. These parallel realities are bizarre and often satirical, parodying popular media tropes and cultural references.

As Sasshi and Arumi navigate these strange worlds, they encounter exaggerated versions of people from their real lives, including family members and acquaintances, who often play pivotal roles in the alternate realities. The series explores their attempts to return to their original world while uncovering the truth behind the phenomenon. The narrative gradually reveals that the alternate realities are tied to Arumi's unresolved emotions and a deeper connection to the Abenobashi district itself.

Sasshi is characterized as a brash, perverted, and resourceful boy with a strong attachment to Arumi, while Arumi is more level-headed and pragmatic, often serving as the voice of reason. Their dynamic shifts as they confront personal insecurities and the complexities of their friendship. The series balances its comedic and absurd moments with emotional depth, particularly as it delves into themes of nostalgia, growing up, and the impact of change on personal relationships.

The plot progresses through episodic adventures in various genres, each with its own self-contained story, while maintaining an overarching narrative that ties the worlds together. The series culminates in a resolution that addresses the origins of the alternate realities and the characters' emotional growth, providing closure to their journey.