"Tekkaman Blade: Missing Link" serves as a direct sequel to the original "Tekkaman Blade" series, bridging the narrative gap between the main series and its follow-up, "Tekkaman Blade II." The story is set in a future where humanity faces an existential threat from the Radam, an alien species that seeks to conquer Earth by transforming humans into Tekkamen, biomechanical warriors under their control. The protagonist, D-Boy (Takaya Aiba), is a Tekkaman who retains his humanity and fights against the Radam to protect Earth.

The narrative begins with D-Boy recovering from the climactic battle against the Radam, which left him in a comatose state. As he regains consciousness, he discovers that the Radam threat has not been fully eradicated. A new faction of the Radam, led by a mysterious and powerful Tekkaman named Omega, emerges to continue the invasion. Omega possesses advanced abilities and a deeper connection to the Radam's origins, posing a significant challenge to D-Boy and the Space Knights, the organization dedicated to defending Earth.

Throughout the series, D-Boy struggles with the physical and psychological toll of his transformation into Tekkaman Blade. His body is deteriorating due to the strain of his Tekkaman powers, and he faces internal conflict over his identity as both a human and a weapon against the Radam. The Space Knights, including key members like Noal Vereuse and Aki Kisaragi, provide support, but their resources are stretched thin as they confront the escalating threat.

The plot delves into the origins of the Radam and the Tekkaman system, revealing that the Radam's invasion is part of a larger, more complex plan tied to their survival as a species. Omega, who serves as the primary antagonist, is revealed to be a former human who willingly embraced the Radam's transformation, believing it to be the key to humanity's evolution. This ideological clash between D-Boy and Omega forms the core of the narrative, exploring themes of identity, sacrifice, and the cost of survival.

As the conflict intensifies, D-Boy is forced to confront his own limitations and the possibility that his fight against the Radam may come at the ultimate cost. The series builds toward a climactic showdown between D-Boy and Omega, with the fate of Earth hanging in the balance. The resolution of this battle sets the stage for the events of "Tekkaman Blade II," leaving key questions unanswered and the future uncertain.

"Tekkaman Blade: Missing Link" expands on the lore of the original series while maintaining its focus on high-stakes action and character-driven drama. It provides a deeper exploration of the Radam's motives and the ethical dilemmas faced by those who fight against them, making it a crucial installment in the "Tekkaman Blade" saga.