This includes spoilers!
The film Princess Mononoke revolves around saving the spirit of the forest that the villagers live by. There are several demon spirits that take the form of animals and other creatures that cause death and destruction in the forest and surrounding villages. Ashitaka fights to save the spirit of the forest by destroying the demons that are causing the destruction. For example, the wolf spirit raised Princess Mononoke (also known as San) since she was a baby and acts to protect the spirit of the forest. After Ashitaka saves San from a village that is trying to kill her and her wolf spirit mother, he is shot. The spirit of the forest heals his bullet wound but leaves his curse from a demon. The humans that live in villages surrounding the forest are preparing to wage war on the spirits of the forest. This could be shown in an environmental studies class, and students can discuss how the story demonstrates humans' disregard for nature and how they continue to cut down trees and destroy forests that contain so much life in them. Towards the end of the movie, San, the wolf spirits and the boar spirits engage in a battle against the humans, while Ashitaka travels to the human village where the women have stayed behind. He finds the village being attacked by samurai, and travels back to the battle to gather the leader of the village who is leading the attack on the forest. He finds the remains of many humans and boar spirits, and learns that the leader of the army sacrificed many humans in order to kill more of the boar spirits. Ashitaka travels with a wolf spirit to save San and the spirit of the forest. Ashitaka explains to the leader of the humans that he wants for them all to be able to live in peace with the forest, The wolf spirit mother saves San from a demon, and the spirit of the forest appears. The leader of the humans kills the spirit of the forest and the humans steal its head. The spirit of the forest becomes a demon creature and begins searching for its head, but everythign it touches starts to die. This could be used to discuss with students the ramifications of destroying forests and other parts of nature, and that without them we cannot survive. At the end of the film, Ashitaka and San fight to return the head of the spirit, and in return it removes the curse of the demon from Ashitaka. The spirit disappears and the land around the village begins to grow and flourish, reminding the villagers that they need to work together with nature to thrive.