It's a story about the loss of innocence and displacement of identity in the frightening urban jungle of a modern society targeted by the forces which are ultimately an allegory for our own latent darker nature, but also about rising above loss and forging your own way in the world through the simplest little things like love, friendship, bravery, and determination. It's also a story about jumping through the air on a motorcycle to synchronized explosions.
Well, that's only if they really want to know. Usually I just say "It's cool, we should watch some" and that does it.