Trivia

The three siblings (Riku, Umi, and Sora) mean "Land, sea, and sky" in Japanese.

Backstory - During the Korean war Japanese merchantmen and crew played a logistical role by ferrying men and supplies, and as such incurred losses in men and material.

There's a French theme in this movie. The clubhouse Quartier Latin refers to the Latin Quarter in Paris. On one of the desks, there's a French-Japanese dictionary. Umi's nickname is Mer, both of which means "sea" in Japanese and French respectively. Poppy Hill is supposed to be named Coquelicot Hill, coquelicot being French for "poppy". Both Poppy and Mer were removed from the official English subtitles for the movie.

The flags that Umi raises mean U and W in international flag language. The two letters mean, "I wish you a pleasant voyage". At one point, Umi raises the flags that spell out Hokuto, which Shun translates for the audience. Shun's flags on the tugboat say UW MER, which are seen again in Sachiko's painting.

Roughly a year before the film's release date, producer Toshio Suzuki nearly removed Gorô Miyazaki from the film after being dissatisfied with the direction of the film. During this time, Hayao Miyazaki offered to take over the movie if the younger Miyazaki was unable to revise it satisfactorily. Goro was given three days to come up with adjustments to the film. On the third day after receiving no new ideas, the elder Miyazaki sent him a painting of the protagonist making huge strides on a bridge. This helped inform him that the issue was the characters' lack of personalities, and how he should alter it. Goro then presented these changes and was allowed to complete the film.