There's something powerful about Roger Ebert's review of Grave of The Fireflies. He actually covers quite a few topics in the eight and half minute piece: how animation can tell a more real story than live actors, how the (apparently) more crude looking Anime is just as powerful as the most technically advanced Hollywood animated flicks, what the heck a Pillow Scene is and more. Heck, he touches on what the role of art is. Most importantly, he manages to introduce you to a form of film you'd likely dismiss, all without coming across as preachy or holier than thou.
The film itself is considered one of those have to watch it once type of movies. Gut wrenching, but supposedly worth it. I'm not sure I'm signing myself up so quickly for that experience. (That's how I felt about A Beautiful Mind - so glad I saw it; never again). But watching the review is a no-brainer. You can consider it your art lesson for the day.