Instructions
Turn on your PlayStation 3. Click on the icon for "PlayStation Store." Scroll down the menu and click "Add-Ons."
Click on the "Add-Ons" icon on the left side of the list of options. Select "M-Z/#" to bring up that menu of games. Scroll through the list of games that come up and select the icon for "Naruto: Ulimate Ninja Storm." This will bring up a list of downloadable content.
Click on the icon for Tayuya. Select "Download" to unlock her character. Repeat this process by clicking on the icons for Jirobo, Kidomaru and Sakon. This will lock all members of the "Sound Four."