 He wrote the script shortly after filming "Dersu Uzala" in 1975, and then "let it sleep" for seven years.During this time, he painted storyboards of every shot in the film (later included with the screenplay and available on the Criterion Collection DVD release) and then continued searching for funding.Following his success with 1980's "Kagemusha", which he sometimes called a "dress rehearsal" for "Ran", Kurosawa was finally able to secure backing from French producer Serge Silberman.