Japanese kunai

The Versatile and Deadly Kunai

A kunai is one of the more popular weapons used by ninja second only to a shiruken. It is also a popular weapon used on many instances in the Japanese manga and anime series Naruto written and illustrated by Masashi Kishimo.

The makings of a kunai

Thought to have originally been derived from the masonry trowel, a kunai has many variations from the short kunai (小苦無 shō-kunai) to the big kunai (大苦無 dai-kunai) as well as narrow-bladed, saw-toothed and wide bladed.  Originally used by peasants as a multi-purpose gardening tool and by stone and masonry workers, the blade is crafted from soft iron and left unsharpened except for its tip because the edges are used to smash types of soft materials like plaster and wood and it is also used for digging holes and for prying things.  A kunai though a basic tool, when used as a weapon by shinobi or ninja, can become a multi-functional weapon of the deadliest kind. Ninja use a kunai to gouge holes in walls among other things.


A kunai is normally leaf-shaped wrought blade that ranges from 20 cm to 30 cm in length with handle designed with a ring on the pommel for attaching rope. The means to attach a rope enables the kunai to act as a spear when strapped to a stick, it is utilized as a grip, tying it to the body to conceal the weapon, as a metal spike for climbing and as a Chinese rope dart.

A practical and efficient weapon

Many of the weapons used by ninja were adapted from farming tools. Kunai were affordable and widely available farming tools that had a useful size and weight and could also be easily sharpened, it was easy to convert the tool into a weapon. The kunai is larger and heavier with the grip being ideal for hand to hand combat compared to a shiruken.

Kunai in popular fan fiction

A kunai can be an efficient harpoon when attached to a rope or a steel chain, a main weapon used by Scorpion, a famous undead ninja character in the Mortal Combat franchise.

In the anime Naruto, the young Naruto himself finds a special takigakure kunai with an extending blade on one side before he is chased by The Taki Kunoichi. The featured variation of kunai had two thin blades, one larger and the other smaller resembling a hachiwara ot a jutte.