Then visit this NHK page, where you'll find the winners of this year's "MiniMini" awards for best short movies. They are all downloadable and run less than five minutes each.
Click on the gold, round button below the bottom right corner of each mini TV screen to view / download them. (The characters on the buttons are 動画 .)
If you're up for it, there's a second contest. You can read about it at this page (sorry, Japanese only). The entry deadline is January 20, so if you're going to enter, you'd better get started.