Tottoi

Coming of age story about a young boy and his bond with an animal, an animal he wants to protect. Both are heavily nature-themed. 

Both are stories about the difficulties of humans and nature/wild animals coexisting. Nausicaa is well known for focusing on the effects of pollution, while Tottoi is a simple story about a boy who discovers and later tries to protect a mother and baby seal in a place where those seals were believed to be extinct.