What Is A Kunai Knife?

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Derived from the trowel used in masonry work, a kunai is a Japanese tool that gained popularity after it was featured in the Naruto cartoon. It is typically associated with the famous historical ninja character.

Peeping into the history of Japanese weapons or tools reveals that a kunai knife was used for digging holes into the walls by the ninjas. It has a rich record of being used as a primary and secondary tool by manga and ninjutsu, the renowned ninja characters.

A kunai knife as a basic tool is commonly seen in martial arts but it is genuinely a multi-purpose weapon. Let’s learn more about it.

Kunai Knife Overview

kunai knife

Originally, a kunai was a multi-purpose tool rather than a knife. It was usually composed of iron and had no cutting edge. While it resembled a modern throwing knife to some extent, it was not designed to act as a throwing knife.

Rather, a kunai possessed a mix of the characteristics of a prybar and trowel. Thus, its main use was prying, digging, and disintegrating the walls. Today, for these tasks, there are dedicated modern tools.

Although not a weapon, it is possible to use a kunai as a weapon today just as you would use a trowel or a prybar. As a weapon, this tool is useful for stabbing although not as effective as a knife. Still, it is primarily used as a blunt tool for hitting, confining and leveraging to take someone down.

Not all kunai knives are the same. Differences are found in terms of size. Some of them are bigger (dai in Japan), while the remaining ones are shorter (sho in Japan). These are the two widely recognized versions of a kunai.

The typical length of a kunai is usually between 20 and 30 cm. Those in Ninjutsu have a length of 20 to 60 cm, of which 40 cm marks the average. Usually, it is a heavy tool to carry.

The Kunai Design

A kunai knife is an untraditional as well as a unique tool in terms of its appearance. It features a straight leaf-shaped blade and a handle with a ring at the end and on the pommel for rope attachment. After all, a circular hole at the end is not just meant for hanging the tool after work; it has practical reasons.

When attached to the handle, the rope facilitates performance with a good grip. It can be wrapped to a stick for having a suitable spear. With this rope, you can even wrap your body for concealing it. At times, you can also use the rope as a piton or as an anchor.

The blade is usually made up of soft iron material. While the tip of the blade is sharpened, its edges are not sharpened. Still, the edges are useful for smashing a soft material such as a plaster. Today, there are many versions or forms of kunai available. Some of them are saw-toothed, thin, and wide.


It is a popular belief that the kunai knives were mainly used as throwing weapons. Although they can be thrown to cause harm, they were primarily used for thrusting and stabbing. This is as per the famous cultural tradition of ninja in which these tools are widely depicted as Japanese knives.

A kunai is often pictured in video games and manga or anime storylines as an ordinary ninja weapon. It is also a weapon that the Scorpion belonging to the Mortal Kombat series tends to use. This character uses a kunai as a spear for his adversary.

Even the character Ibuki in the Street Fighter video game uses the tool. Most ninja and video game characters intermittently affix paper bombs to this tool for triggering explosions.

The main usage of the Kunai was as a gardening tool. Surprisingly, farmers used it for this purpose. The kunai was considered extremely reliable for digging, a job that every warrior does. The knife was also used for stonework by the masons. However, the kunai blade is useful for a variety of purposes, which are as follows:

  • For Climbing: Interestingly, you can use a kunai for climbing hills or mountains. It works by acting as a piton or as a hook to penetrate the rocks a bit for support and grip.
  • In Different Fields: Did you know that many ninja weapons being used were originally used in the farms? This also applies to the kunai weapon. As the kunai blades did not come with high price tags, these knives were considered highly affordable. Thus, they were used not only in farms but also in fighting fields by ninjas who found them to be the simplest and easiest option for having a great weapon. As a weapon, kunai knives are heavier than the ninjas’ shuriken tool. Due to a solid grip, kunai knives are more easily reliable in close combat than the shuriken.
  • For Throwing: Although not meant for it, a kunai knife is surprisingly an ideal throwing knife. Due to its small size, lightweight, and pointed shape, it is easy to throw it from a far distance. Even the finger ring at the end of the handle ensures a proper grip while throwing. The ring also ensures good control over the tool at the time of throwing. Thus, it is common to see this tool as a throwing knife in different contests as well as games across the globe. and the end hole makes it easy to tie a rope at the end of the kunai. Moreover, even the rope that is tied to the other end of the ring makes this tool a precise and lethal throwing knife. It not only facilitates an improved repossession but also ensures stability due to which the knife can be in parallel to the ground while flying. Of the two types of kunai, the smaller ones are more comfortable for throwing.
  • For Stone and Masonry Work: A kunai is tagged as an ideal masonry tool. It can be used easily for breaking rocks and small stones as well as for plastering items. The risk of injury is also less due to the unsharpened edges of a kunai.
  • For Gardening: This is the primitive use of a kunai. In ancient times, farmers used this tool for gardening tasks including digging. Even today, in some regions, it is still used for gardening, farming, and digging holes. Due to the blade’s leafy shape, digging easily results in deeper holes. It is also the reason why users can easily perform tough jobs.

Historic Overview of Kunai Knives

As you can guess, kunai as a multi-purpose tool originated in Japan. As per the records, it was first used as a trowel in the nation during the Tensho age. This trowel was made of iron instead of steel using which the modern kunai is made.

It was unpolished, less sharp than a knife, and extremely affordable. The knife was chiefly used as a masonry, building, and a gardening tool. People used it for prying holes and smashing plaster.

As it was not considered a weapon, the initial Kunai was not sharp. The design featured a spear-like head, a ring on the pommel, and a handle.

Later, the tool evolved to step into the world of weapons. Martial arts experts and ninjas started requesting the weapon makers to make sharp kunai knives using the hard stainless steel material. Despite this, it is alleged that these weapons were still hung in homes and spun in the dirt, masking their novel use.

Contrary to the belief of being used as throwing knives, kunai knives were used outdoors for climbing and in fights for stabbing.

Reasons to Choose a Kunai Knife

Why would you choose the kunai Japanese knife? Well, there are a couple of reasons for the same, which are as follows:

  • Versatile tool with many applications
  • Ideal for outdoor jobs
  • Light and easy to carry
  • A self-defense weapon that flies, stabs and thrusts well
  • Extremely inexpensive as compared to knives

3 Best Kunai Knives on Amazon

9 1/2 ” Metal Ninja Kunai Throwing Knife

9 1/2 " Metal Ninja Kunai Throwing knifeIf you are a knife expert, looking at this knife for the first time will give you an impression of it being only for decorative purposes. However, this is not true. This is because it works well for stabbing and as a trowel, the original uses. You can even use for cosplay and costume contests.

This 9.5-inch kunai comes with a pointy blade that is unsharpened but is still capable of sticking to a soft piece of wood. The handle is wrapped in cloth and is big enough to ensure a good grip. The full construction is of an incredibly soft but real metal and is coated well.

The diamond shape of the blade will attract you if you are looking for a kunai that precisely replicates the Naruto kunai. All Naruto fans will love it. However, the design and weight are such that this kunai should not be used as a throwing knife. It is also not meant for use by kids.


  • Light
  • Good size
  • Well balanced
  • Pointy
  • Affordable
  • Giftable


  • Risk of bent tip although forging can restore its original state
Check Price and Reviews on Amazon


11″ Spikey Metal Ninja Throwing knife

11" Spikey Metal Ninja Throwing knifeThis is a ninja kunai knife designed for throwing but this needs a very careful attempt. It is 11-inch in overall size and a bit heavy due to which throwing has to be a meticulous effort. Thus, it is not meant for kids to throw but for the adults to learn knife throwing.

The knife is ideal for cosplay and costume contests. Its blade is unsharpened but still, the user needs to be careful while using it, as it is quite pointy. The blade’s shape makes you recall a sword due to which it sets apart from the rest of the kunai knives.

The overall construction is of metal with the handle wrapped in cloth and attached to a sturdy ring.


  • Solid build
  • A sturdy and sharp tip
  • Good grip
  • Affordable


  • A bit heavier than normally what is expected
Check Price and Reviews on Amazon


Lystin Naruto Leaf Village Ninja Shinobi Headband and 3PCS Red Ninja Big Kunai

Lystin Naruto Leaf Village Ninja Shinobi Headband with 3PCS White Ninja Weapons Props Big Kunai Plastic Toy for Anime Cosplay (3Pcs White Naruto kunais & Leaf Village Headband)This is a Naruto set that comes with a long Shinobi headband and three big kunai knives. While the headband is made up of an ideal mix of leather for padding, nylon, and bendable metal, the knives are made up of plastic.

All the materials in use seem to be of high quality. This becomes evident when you use the items. Consider this ninja big kunai set if you wish to be a part of a cosplay party or a Halloween costume contest. It is just ideal for children who intend to cosplay Japanese ninja.

The headband is very long due to which there is no need to worry about its fitting. For fitting to your head’s shape, just slightly bend the metal plate. That’s it! The headband is flat due to which it is essential to contour it to your kid’s if the risk of tearing bothers you.

On the other hand, the kunai knives are short, as they are only 5.1 inches long. Still, they are pointy due to which kids should not use them in the absence of adult supervision. As they are small, they are meant to be held not like a knife but in between the fingers.


  • Light
  • A real Naruto set
  • Giftable to kids
  • Highly durable despite the use of plastic
  • Affordable


  • Not for adults
Check Price and Reviews on Amazon


A kunai knife is a multi-purpose tool that is useful for a variety of daily routine tasks. Nevertheless, they are commonly seen in throwing knives contests and martial arts. It is also the most famous weapon that all anime and manga characters use due to its status in the Japanese culture.

There are different varieties of kunai knives available online. You can also buy them with other Naruto or ninja accessories as a set. However, you should buy the one that best fulfills your purpose or requirements. Many of them are only meant for cosplay, while the rest are for some practical uses like throwing and stabbing.