Oh, dear Goddess - that has to be Grave of the Fireflies, the most soul wrenching film I've ever seen. I couldn't stop crying for days afterwards. It was so heartbreaking in that it was true. It tells the story of two young children after their mother is killed by an American fire bomb. The boy is about twelve and his sister is about four and it follows their slow decline into starvation and eventual death. they are sent to live with an aunt, who resents them and the boy decides they are better off without her and exchange a nice house with food for an abandoned shed. The boy feels that they just have to hold on until their father returns. Then he receives word that his father is dead. It just goes downhill from there. It reminded me that there are victims in both sides of a war.
I was so upset by it that eventually I gave the DVD away to Friends of the Library because I would break into tears every time I saw the cover. And yeah, I'm crying now. I have never had a film affect me the way this one did.