Ito Togarashi is a shredded Japanese red chile pepper used as a garnish. The shredded pepper is not crisp and dried but it has a slightly chewy texture. The shreds do have a little bit of heat but nothing drastic.
Image credit: Asian Chef Association
These finely shredded chiles are most often used as a decorative garnish on savory dishes including noodles, sashimi and soups.
If you happen to have a Japanese market in your area then definitely go there first. In the San Jose, Cupertino area there is a great Japanese market named Mitsuwa Marketplace which carries virtually everything Japanese. Also, Hankook Supermarket is an excellent Korean superstore. If you're in the U.S. and you want to buy online you can purchase the similar shilguchu here at Amazon.com.
If you can't find ito togarashi you can substitute one of these alternatives: