The Japanese Sailor is a forty-to-fifty-year-old Japanese Navy ensign who has been patrolling the waters around island in his one-man submarine since World War Two. His true name is unrevealed, but since his radio broke, he has been cut off from communication from his superiors and is completely unaware that the war has ended. He is quite adept at English, having attended UCLA and having watched captured American movies starring John Wayne. On the island, he captures all of the castaways except for Gilligan and the Skipper and puts them in bamboo cages booby-trapped with live grenades. However, Gilligan waits for the sailor to fall asleep in order to steal his rifle and eyeglasses, rescuing everyone as a result while the Skipper is trying to dig everyone out of the cages. The sailor flees the island, struggling to reach the ocean from the lagoon without his glasses. Several months later, the Skipper, Ginger and Mr. Howell remember their escape from the sailor much differently than Gilligan's memory of the incident.
- The Japanese Soldier was played by character actor Vito Scotti who returned in the second season playing Dr. Boris Balinkoff in the episode The Friendly Physician.
- The character portrayal, while humorous to some, is considered racist by others as it played upon common themes and stereotype portrayals in U.S. WWII era propaganda films and cartoons. The episode is sometimes left out of syndication rotation in some markets due to the perceived racially insensitive nature of the character.
- The look of the Japanese Sailor bears an incredible resemblance to published U.S. WWII propaganda images, including those drawn by Dr. Seuss.
- Since the sailor has been cruising around the island since World War II, it's unrevealed how he escaped capture by the Air Force who used the island as a landing strip or how Wrongway Feldman and Dubov avoided getting captured by him.
- The Japanese Sailor is likely based on Hiroo Onoda, a Japanese soldier who remained on duty in the Philippines for more than twenty years after the end of World War Two.
- The Japanese Navy didn't own any one-man submarines.