StarTropics

Mike Jones, a 15-year-old boy from Seattle and the captain of his high school's baseball team, travels to visit his uncle, archaeologist Dr. Steven Jones, at his laboratory on C-Island in the South Seas. When Mike arrives at Jones's home in the tropical village of Coralcola, he finds that he has disappeared. The chief of Coralcola gives Mike a yo-yo to defend himself, and Jones's robot Nav-Com permits Mike to use his submarine to search for him.

On a nearby island, Mike finds a bottle with a message from Jones, stating that aliens have abducted him. While fighting monsters and traveling across the isles of the South Seas in search of Jones, Mike encounters various characters, including a parrot and a mother dolphin looking for her son. Eventually, a whale swallows Mike and the submarine; in its belly, Mike encounters Jones's assistant, who confirms that aliens abducted him and that out of fear, he did not give Mike all possible help when they met earlier. After escaping the whale, the assistant gives Mike a special code, enabling Nav-Com to track Jones's location.

Mike follows the signal to ruins which contain the wreckage of an alien escape pod. Shortly after, Mike finds Jones, who explains that he discovered the escape pod some time ago, which came from the faraway planet of Argonia. The pod contained three magic cubes, which are now in the possession of the aliens' leader, Zoda. After infiltrating their spaceship, Mike recovers the three cubes and confronts and defeats Zoda, then escapes as the spaceship self-destructs.

After Mike returns to C-Island, the cubes are placed together and a group of children appear. Their leader, Mica, explains that they are the last of the Argonians, as Argonia was destroyed, and that her father, King Hirocon, sent them to Earth to live in peace. The village chief invites the children to live with them in Coralcola, which they accept.