According to Horikawa, the film is set around five years after the original TV anime, which launched originally in October of 2014.
The original SHIROBAKO series aired on Crunchyroll over the course of 24 episodes from October 2014 to March 2015.
The film will be at least 120 minutes, Horikawa said, explaining that the film required too many elements for the typical 90 minutes allotted for an anime film.