 Miyazaki initially refused, but agreed on the condition that he could direct.Miyazaki's imagination was sparked by the mercury poisoning of Minamata Bay and how nature responded and thrived in a poisoned environment, using it to create the film's polluted world.Miyazaki and Takahata chose the minor studio Topcraft to animate the film, as they believed its artistic talent could transpose the sophisticated atmosphere of the manga to the film.