To unlock the 4th jutsu, go to the ninja academy (where you first get the wind scroll and two jonins[the green ninjas]), at the right side of the second jonin, there is a small crawlway then go through it, inside there is a giant scroll which gives you permanently the 4th jutsu and a 1up.

The 4th jutsu of Naruto is the nine-tailed fox chakra, for Sasuke is the lion combo, and for Kakashi is lightning blade. Thnx for reading, I hope this helps.