A Foreign Love Affair is about the son of a yakuza mob, Ranmaru, who gets married for convenience to a yakuza daughter, Kaoru, on a cruise ship in Italy. Because they are Japanese they are the center of attention on the boat. On their wedding night, the couple fight and Kaoru kicks him out of their room. Ranmaru goes to the boat's bar and fights with some yakuza. He is assisted by a blond Italian man who can speak Japanese, Alberto, and as a thank you Ranmaru asks Alberto if he wants a drink in the bar. They get thoroughly drunk and have sex. The next morning, Ranmaru finds out that Alberto is the ship's captain.