"B't X Neo" is a sequel to the original "B't X" series, continuing the story of Teppei Takamiya and his mechanical companion, B't X. The narrative picks up after the defeat of the malevolent Machine Empire, with Teppei and X embarking on a new journey to uncover the mysteries surrounding the resurrection of the empire and its connection to a powerful entity known as the Messiah. The series delves deeper into the lore of the B'ts, advanced mechanical beings bonded with human partners, and explores the ethical and existential dilemmas tied to their creation and purpose.

Teppei, a skilled martial artist, remains the central protagonist, driven by a strong sense of justice and loyalty to his friends. His bond with X, a B't with a unique will and personality, is central to the story, showcasing their growth as partners and individuals. The duo faces new adversaries, including the enigmatic and formidable Raphaello, who seeks to harness the power of the Messiah to dominate the world. Raphaello's motivations are rooted in a tragic past, adding layers of complexity to his character and the overarching conflict.

The plot unfolds across multiple arcs, each introducing new allies and enemies. Among the key characters is Karen, a scientist with a deep understanding of B't technology, who aids Teppei and X in their quest. Her knowledge becomes crucial in deciphering the secrets of the Messiah and its potential to either save or destroy humanity. The series also revisits characters from the original series, such as Hokuto and Aramis, who play pivotal roles in the unfolding events.

Themes of sacrifice, redemption, and the coexistence of humans and machines are explored as the story progresses. The narrative builds toward a climactic confrontation between Teppei and Raphaello, with the fate of the world hanging in the balance. The resolution of the conflict hinges on the choices made by the characters, emphasizing the importance of free will and the consequences of one's actions.

"B't X Neo" maintains a balance between action-packed sequences and character-driven storytelling, offering a continuation that expands on the original series' foundation. The series appeals to fans of science fiction and mecha genres, providing a cohesive and engaging narrative that ties together the threads of its predecessor while introducing new elements to keep the story fresh and compelling.