Water Needle Training is training projectile for users of the Gentle Fist technique. It's damage like all other
Gentle Fist techniques scales on Strength providing a nice single target ranged technique for training at lower levels. Once you level this up to Level 2 it becomes Revolving Heavens Technique.
You need to be at least level 13 with Taijutsu Mastery and be in the Leaf Village.
How To Obtain
Enchant a Blank Scroll into a Sealable Scroll I and purchase it from the Leaf Village Scroll Shop under the Leaf Hidden Jutsu tab.