Kunai

A kunai (苦無 kunai^?) is a Japanese tool possibly derived from the masonry trowel.^[1] Two variations are the short kunai (小苦無 shō-kunai^?) and the big kunai (大苦無 dai-kunai^?). It is a good example of a very basic tool which, in the hands of a martial arts expert, could be used as a multi-functional weapon.^[2]

It is commonly associated with the ninja, who used it to gouge holes in walls.^[1]

Many ninja developed weapons that were merely adapted farming tools, not unlike those used by Shaolin monks in China. Since kunai were cheaply produced farming tools of a decent size and weight, and could be easily sharpened, they were readily available to be converted into simple weapons.

As a weapon it is larger and heavier than a shuriken, and with the grip could also be used in hand to hand combat more readily than a shuriken. In addition, it could be used for climbing, as either a kind of grappling hook, or a piton.^[2]

As with the ninjutsu, the exaggeration persistent in ninja myths played a large role in creating the current popular culture image of kunai.