Kenta Sanada is the son of Professor Sanada, a physicist who discovered the powerful Beamler energy source. When his father committed suicide to prevent the evil Dokuga organization from seizing his research, Kenta became Dokuga's next target. A colleague of his father rescued him, bringing him aboard the teleporting fortress Good Thunder. There, Kenta joined the crew battling Dokuga's global influence.

Initially curious and impulsive, Kenta's inquisitive nature often led him into danger aboard Good Thunder. The adult pilots—Shingo Hojo, Killy Gagly, and Remy Shimada—mentored him, providing combat and strategic training that helped him gradually mature. He occasionally piloted components of the giant robot GoShogun when the primary pilots were unavailable.

Kenta possessed a natural affinity for machines, showcasing technical skill and an emotional connection to robotics. His robotic tutor, OVA, served as a maternal figure, offering education and discipline while she evolved beyond her programming to support the crew. Kenta frequently expressed distress over the destruction of machines in the conflict, though he eventually accepted it as necessary in the war against Dokuga.

The series revealed Kenta's intrinsic link to Beamler energy, originating from a meteorite at the Tunguska impact site. This energy was a test of humanity's readiness for interstellar contact. As the narrative unfolded, Kenta's connection deepened, culminating in the revelation that he was an alien entity embodying Earth's collective consciousness—encompassing life, sentient machines, and the planet itself. In the climax, he confronted and defeated NeoNeros, the malevolent manifestation of Beamler energy. Kenta then departed Earth in GoShogun to return to his home planet.

In the film sequel *The Time Étranger*, set decades later, Kenta does not appear directly but is referenced through Remy Shimada's memories during a critical life event, his legacy remaining a foundational part of her history.