"Appare-Ranman!" is a manga series set in the late 19th century, blending historical elements with action, adventure, and comedy. The story centers on Appare Sorano, a socially awkward but brilliant inventor, and Kosame Ishikki, a skilled but timid samurai. After a series of mishaps, the duo finds themselves stranded in the middle of the ocean, eventually washing ashore in the United States. With no money or means to return to Japan, they decide to participate in the Trans-America Wild Race, a high-stakes cross-country automobile race offering a substantial cash prize.

The race serves as the primary narrative framework, introducing a diverse cast of competitors, each with unique motivations and backgrounds. These include skilled drivers, cunning strategists, and individuals with personal vendettas. As Appare and Kosame navigate the challenges of the race, they encounter various obstacles, from treacherous terrains to rival racers willing to sabotage their progress. The duo's contrasting personalities—Appare's eccentric genius and Kosame's cautious pragmatism—create a dynamic partnership that drives much of the story's humor and tension.

Throughout the series, the narrative explores themes of ambition, perseverance, and cultural exchange, as the characters confront their own limitations and aspirations. The race also serves as a backdrop for deeper conflicts, including political intrigue and personal rivalries, adding layers of complexity to the plot. The manga balances its adventurous tone with moments of introspection, particularly as Appare and Kosame reflect on their identities and the choices that have brought them to this point.

The artwork complements the story's energetic pace, with detailed depictions of the race's settings and the inventive designs of the vehicles. The characters are distinctively rendered, with expressive designs that highlight their personalities and roles in the narrative. The series maintains a consistent focus on the interplay between its central characters and the evolving challenges of the race, ensuring a cohesive and engaging storyline.