How do you play as half Shukaku Gaara in Naruto Ultimate Ninja 3?

I%26#039;ve heard that when highlighting Gaara, or anyother character with a second form, you hold select. I keep doing this but it doesnt work. Do I have to do something special before it%26#039;ll work? In story mode or something else?|||you have to unlock all the characters before you can do that