Kunai Knives are the most used weapons in Naruto. It has a diamond shaped head with a handle usually coated in fabric for easier grip and an open holed end that can serve a variety of uses, it may be used to attach strings as well as exploding tags and it is a useful way to spin using your fingers which other than looking cool, is useful to switch from one use of the knife to another. Kunai Knives can be used as direct hand to hand knife and throwing knife.
 Use 1: Hand to Hand Combat
There are two ways to handle the knife in hand to hand battles. One is by grasping it with the sharp end away from you. This is the way most ninjas use it. In this way, both offense and defense is easily maintained. Another way is with the sharp end pointing towards your body. This is just like holding a really small sword. Not very many ninjas use it this way and if they do it is only for temporary offense. By using it this way a shinobi loses much of their defense. The main reason for using it this way is to make a direct stab at someone usually from point blank range.
 Use 2: Throwing Knives
The second use is to throw the kunai. This is just frequently used by ninjas as the other use. Sometimes when throwing kunais it is used in combination of throwing shurikens as well. Though kunais can deal more damage it is usually less accurate with only one sharp end so shurikens is used in combination to increase chance of hitting. When throwing kunais, though it is humanely impossible, the shinobis are able to throw them where they fly in straight pinpoint manner towards the target.