Kunai, along with the shuriken, is one of the most common ninja tools used within the ninja era. It is a black dagger designed for thrusting and stabbing, though it can still do some damage if thrown despite not being designed for it, and is about the length of one's hand.
Many shinobi attack by attaching an explosive tag to the blade. The kunai is usually thrown so that it lodges in an object near the target, and then the explosion from the attached tag destroys the target. These weapons are particularly used in regular hand-to-hand combat proving to be a useful weapon. Shinobi appear to favour them so much due to both their sturdy and dependable nature, as well as their evident versatility