Adam Nasenkopf is the robot creation of his father, Professor Nasenkopf, a Nobel Prize-winning scientist of Polynesian Maori descent. The professor's experiences with racial prejudice in Germany and the United States shaped his worldview.

Physically resembling Astro Boy, Adam serves a distinct purpose. He boards the Marine Express on its test run alongside his creator and adopted human brother, Rock. Following his creator's directive to prevent destructive development and pollution in Polynesia, Adam moves to destroy the train.

During the mission, Adam reaches the train's computer room but is briefly interrupted by Milly, a fellow passenger revealed as a cyborg. The journey catapults the train through dimensions to the ancient sunken continent of Mu, 10,000 years in the past. There, they confront Prince Sharaku, an alien invader planning to exploit the sea floor's resources using the train.

In the climax, Adam fulfills his original mission by destroying the Marine Express. This act causes his own destruction alongside Professor Nasenkopf and Sharaku. It halts the exploitation of undersea resources and thwarts the alien's plans, enabling the resolution of the conflict and the restoration of Mu's sovereignty. Adam's actions directly reflect his creator's environmental concerns and opposition to cultural imperialism.