This achievement is one of the easiest in the game. If you have one, pick up a spare controller, enter free battle and go to player vs. player. For yourself, select Hinata and for the other person just hit
to randomize it. If you don't have a second controller that's fine. Go against a computer and set the difficulty to Super Easy. Once you're in battle, use Hinata's jutsu (
) on the opponent and it will give you 64 hits. Way more than you need for the achievement. Either way, it should unlock seconds after you get your 64 hits.
(EDIT: When selecting Hinata, make sure to change her jutsu to Protective 8 Trigrams 64 Palms in order to get the 64 hits. Credit to Gerbasgamer for the tip.)