A Kunai is a small weapon. The Kunai is similar to the Knife, accept the Kunai has a small hole at the end making it similar to some kind of crowbar. Many ninjas used the Kunai very often. This weapon is not usually used in wars. A smart thing to do with a Kunai is to even add a chain to it, so it can increase the range. The Kunai is often seen in Japanese anime such as Naruto. The Kunai can also be a decent grappling hook for climbing.