"Dimension W" is set in a future where humanity has harnessed the power of a fourth-dimensional energy source known as "Coils." These Coils, developed by the New Tesla Energy corporation, revolutionized society by providing unlimited, clean energy. However, the technology also brought unintended consequences, including illegal "Numbers Coils" that operate outside regulated systems and pose significant risks.

The story centers on Kyouma Mabuchi, a gruff and resourceful "Collector" who specializes in retrieving illegal Coils. Kyouma harbors a deep disdain for Coils and the technology-driven world they represent, preferring to rely on traditional methods and tools. His life takes a dramatic turn when he crosses paths with Mira Yurizaki, an advanced android with a human-like appearance and a mysterious past. Mira is designed to operate without a Coil, drawing energy directly from Dimension W, the enigmatic source of Coil technology. Together, they form an unlikely partnership to investigate the darker side of Coil technology and uncover the secrets of Dimension W.

As Kyouma and Mira delve deeper into their investigations, they encounter a web of corporate intrigue, scientific experimentation, and hidden agendas. Key figures include Loser, a rogue scientist with ties to the creation of Coils, and Mary, a young girl with a connection to Mira and the origins of Dimension W. The narrative explores themes of technological dependency, ethical boundaries, and the consequences of unchecked innovation.

The series balances action, mystery, and character development, with Kyouma's hardened demeanor contrasting sharply with Mira's innocence and curiosity. Their evolving dynamic drives much of the emotional core of the story, while the overarching plot delves into the mysteries of Dimension W and its implications for humanity. The narrative builds toward a climactic confrontation that ties together the personal struggles of the characters with the larger societal and scientific questions at play.