Otto and Leo are two men from Germany who have launched a successful business in which they import koi, the beautiful Japanese fish, for collectors in their native land. While on a business trip to Japan, Otto and Leo meet Ida, a German tourist who is studying fashion design. Ida begins traveling with the two men, and surprisingly develops an infatuation with the rumpled Otto instead of the handsome Leo. When Ida discovers she's pregnant with Otto's child, the two marry, and upon their return to Germany, Ida attempts to join in the business by creating a line of scarves decorated with koi patterns. However, the honeymoon proves short-lived, and Ida's presence creates a rift between Otto and Leo, as the latter sets up his own concern, raising koi with his new bride, Yoko.