Namco Bandai just released a demo for Naruto Shippuden: Ultimate Ninja Impact in Japan and you don’t even need to log on to PlayStation Network to get it. Go here and click on either "download A" or "download B" (red or blue buttons). Then, copy the files to your PSP and you’re ready for rasenshuriken action.
The downloadable demo includes one stage of Ultimate Road (the game’s story mode) and a taste of tag missions. You can use Naruto, Sakura, Kakashi, Guy, Rock Lee, and Gaara in tag mission mode. As of now, Namco Bandai have not announced an English demo.
Naruto Shippuden: Ultimate Ninja Impact comes out on October 11 in North America and October 20 in Japan.