The 2001 Studio Ghibli film Spirited Away has an incredibly rich plot. One that led it to be the longest animated film to every win Best Animated Feature (125 minutes). As it turns out, the film was not made with a script. In fact, director Hayao Miyazaki's films never have scripts, once discussing his creative process as follows:
"I don't have the story finished and ready when we start work on a film. I usually don't have the time. So the story develops when I start drawing storyboards. The production starts very soon thereafter, while the storyboards are still developing. It's not me who makes the film. The film makes itself and I have no choice but to follow".
In other words, Miyazaki himself does not know where the plot is going, and he lets it happen organically. The result has been some of the most compelling animated feature (or live-action) of all-time! Stay tuned!