There aren't a lot of surprises here: no fancy loop-backs or even such basics as cross-cutting all that much. We start at the beginning and work our way chronologically to the end, skipping around between different characters as the narrative demands. It may not be revolutionary, but it does the job. With Kurosawa trying to get the whole world to see his little flick, he wasn't about to get cute with the narrative structure.
He also sticks pretty firmly to the notion of realism, keeping the music to a minimum and emphasizing the natural qualities of the scenery and the village. It helps stress the war to come—we get lots of flowers and pretty glades before the rainstorm at the end that pounds them flat—but he doesn't want us to think there's anything embellished or otherworldly here. This is a just-the-facts-ma'am movie, and while we sometimes see amazing things, they aren't things we could mistake for a dream, a vision or anything out of this world.