Planetarian: Storyteller of the Stars

Production

Asmik Ace producer Hiroyuki Aoi brought the Planetarian original net animation series and the Hoshi no Hito film to David Production. Aoi explained that the studio was selected because of how much they honor the original material when creating an adaptation. Director Naokatsu Tsuda was part of the team deciding on a director for both projects. After reviewing several candidates, Tsuda put himself forward for the role, partly because, as a fan of Key's works, he did not want to let the chance slip away. Tsuda has admired Key's creations ever since he first encountered Kanon, and their influence has stayed with him. Tsuda also co-wrote the screenplay with Shogo Yasukawa and handled the storyboard. He had previously written a script for an episode of the 2014 series JoJo's Bizarre Adventure: Stardust Crusaders, which he also directed. However, while working on the storyboard for Planetarian, he found he could sink deeper into the story than he could with JoJo's Bizarre Adventure, which helped him keep his vision intact. For the script, Tsuda and Yasukawa brainstormed often. After those sessions, Tsuda gave Yasukawa a rough outline, which Yasukawa would then organize. They would later meet several times to refine the script. Tsuda found the collaboration smooth because both had worked on JoJo's Bizarre Adventure before. Tsuda aimed to adapt the "Hoshi no Hito" short story from the Planetarian light novel. He also wanted to include scenes from the "Snow Globe" and "Jerusalem" stories, but once he began writing, he decided those additions felt out of place. He did, however, weave in small references to those stories within the film.