Princess Mononoke (1997)
Dir. Hayao Miyazaki
There's often an environmental message in Hayao Miyazaki's works, but it's much more aggressive in Princess Mononoke than in any Ghibli film that he'd made prior, and because of that it feels less safe.
It's Nature versus Industry in a war that neither side can win. Trapped in the middle is a village Prince named Ashitaka. The youth is unwilling to take sides, but at the same time is determined to put an end to the conflict. He's even prepared to die, if necessary.
The girl with the warpainted face on the cover is San. She sides with the animals, which gives her a very direct focus, initially, but, for reasons that are too spoilery to go into, she's also one of the more interesting characters.