"Neppu Kairiku Bushi Road" is a 12-episode anime series set in a post-apocalyptic world where the Earth has been drastically altered by environmental collapse. The narrative unfolds in a future where the planet is divided into two distinct regions: the scorching, desert-like "Neppu" (Hot Wind) and the submerged, waterlogged "Kairiku" (Sea Continent). Humanity survives in these harsh conditions by relying on advanced technology and massive, mobile fortress cities called "Bushi," which are powered by a mysterious energy source known as "Karyu."

The story centers on a young man named Ryuho, a skilled swordsman and pilot of the Bushi "Karyu." Ryuho is driven by a desire to protect his homeland and uncover the truth behind the world's catastrophic transformation. Alongside him is his childhood friend, the determined and resourceful Shizuku, who serves as a navigator and strategist. Together, they navigate the treacherous landscapes of Neppu and Kairiku, battling rival factions and monstrous creatures known as "Karyu Beasts," which are drawn to the energy of the Bushi.

As the series progresses, Ryuho and Shizuku encounter a diverse cast of characters, including the enigmatic warrior Kaisa, who harbors secrets about the origins of the Karyu energy, and the ambitious warlord Raiga, who seeks to dominate both Neppu and Kairiku. The narrative explores themes of survival, loyalty, and the consequences of humanity's exploitation of natural resources. The characters' journeys are intertwined with the mysteries of the Karyu energy, which holds the key to the world's past and future.

The plot is driven by a series of conflicts, alliances, and revelations, culminating in a climactic battle that forces the characters to confront the true nature of the Karyu and its connection to the Earth's devastation. The series balances action-packed sequences with moments of introspection, as the characters grapple with their roles in a world teetering on the brink of collapse. "Neppu Kairiku Bushi Road" presents a compelling narrative that combines elements of science fiction, adventure, and environmental allegory, offering a thought-provoking exploration of humanity's relationship with its environment.