Author Existence Failure: Seiichiro Ujiie, who served as a member of the film's production committee, died four months before the film's release due to multiple organ failure.
Creator Cameo: Goro Miyazaki provides the Japanese voice of Isogo High's world history teacher.
No Export for You: Eventually averted. Disney, Studio Ghibli's usual distributor in North America, neglected to pick up this movie, leaving its international future undetermined. This raised speculation on whether Disney didn't want the rights to Poppy Hill due to certain themes clashing with their family-friendly image, or they just didn't think it was "fantasy"-esque enough to be profitable. However, GKIDS, an independent animation distribution company that had previously received theatrical rights to most of the Ghibli films, picked up Poppy Hill, with Studio Ghibli preparing a dub for it. The movie had a theatrical release at March 15th, 2013, with a DVD and Blu-Ray release following September 3rd the same year.
Non-Singing Voice: In the Mexican Spanish dub, Shiro Mizunuma's singing voice is provided by Luis Leonardo Suárez.
Posthumous Credit: Seiichiro Ujiie is given a credit in this film, having been involved in its production.
Real-Life Relative: In the English dub, Chairman Tokumaru is voiced by Beau Bridges, while his daughter Emily voices Tokumaru's assistant.