Do: The Ultimate Armor for Protection

All parts of Japanese protective armor are vital, but one of the major components is the Do or cuirass. It is a breastplate often worn by the Ashigaru (foot soldiers) of Feudal Japan for protection and defense.

The armor contrasts with its European counterparts since the Do was primarily designed to provide proper mobility. It was also principally made to add layers of protection to the Samurai’s torso.

Looking Into the Past of the Do

Similar to other protective armor, the Do boasts of a rich lineage tracing back to ancient Japan. Originally, the breastplate was crafted for mounted archers. Yet to improve its functions and for better defenses, it went through multiple significant optimizations.

Samurai with armor on horse

Its upgrades and transformations were influenced by progressing combat techniques and warfare. So, the Do ended up evolving into a protective breastplate that accommodates the ever-changing needs of Samurai on the battlefield.

Early Centuries and the Evolution of the Do

The earliest Do was manufactured as early as the 4th century, and the earliest known pieces were pre-Samurai types. These were Keikou for the cavalry and Tankou for the foot soldiers, which were constructed from iron plates. The pieces were linked together using strong leather thongs.

From 794 to 1185 of the Heian period, the Do evolved and upgraded into the more familiar Japanese armor worn by the Samurai. Armorers began using hardened leather integrated with iron for better construction. They also put lacquer to use for weather-proofing certain areas of the armor.

By the era, the Do breastplate landed the shape, style, and design recognized by everyone – the Samurai armor. It started with iron scales or leather for its construction. Eventually, armorers used leather and then silk lace for connecting the individual Kozane or scales.

Modifications Made on the Do

The 16th century brought forth the Nanban Trade between Japan and Europe. It was a time when the Samurai took advantage of acquiring European cuirasses, which they merged with domestic armor.

Armorers decided to combine the armor to better protect the Samurai against the newly-introduced weapons. These were matchlocks or Teppo/Tanegashima.

In 1543, battle strategies improved while Teppo became a common sight on the battlefield. Because of these, armorers needed to upgrade the construction of the Do. Instead of ancient lamellar, they started using plate armor built from steel and iron plates.

The outcome was the Tosei Gusoku (new armor) and the bullet-resistant Tameshi Gusoku. Creating these armor allowed the Samurai to rush into battle despite the growing use of firearms.

Wars and battles increased during the Sengoku period. So, more Ashigaru were recruited, which meant more armor had to be produced.

Armorers then created a large number of Okashi and Tatami Do. The latter is a type of armor that is foldable.

Last Use of the Japanese Armor

The Sengoku period ended when Tokugawa Ieyasu subsequently rose as the Shogun in 1603. By this period, the warriors continued using lamellar and plate Do to symbolize their status as Samurai. However, the use of traditional protective armor was no longer needed.

During the Edo period, when battles declined further, concealed and lightweight armor became popular since personal protection was still necessary.

There were instances of assassinations, civil strife, duels, and peasant revolts in the area which required continuous use of armor. The Tatami Do, Kusari Katabira (chain armor jackets), and armored sleeves are among the protective gear that can be worn under regular clothing.

Samurai of the Edo period often handled internal security. So, they still wore a variety of Kusari Gusoku (chain armor), shin & arm protectors, plus Hachi Gane (forehead protectors).

The Samurai continued equipping traditional armor until the end of the Meiji period (1860s). Its last widespread use was during the Satsuma Rebellion (1877).

Purpose of the Do

Similar to other protective gear, the primary purpose of the Do is to protect a Samurai. Specifically, it shielded one’s torso from enemy attacks thanks to its construction of overlapping metal plates. Its design allowed the user to enjoy maneuverability and flexibility without compromising solid protection.

With other components like shoulder guards, back plates, and waist plates, the Do offered adequate coverage to safeguard vital organs.

Materials Used for Crafting the Do

The breastplate usually consisted of leather, but eventually, iron scales/plates were integrated. Its scaling effect gave the Do enhanced durability while creating a tough exterior to protect against piercing shots and blows.

Additionally, the Japanese cuirass received a lacquer finish to make it waterproof. It also helped prevent damage or weakening when the Do was exposed to elements.

Generally, these types of armor had iron, lacquer, or leather from ox, deer, or horse. It also consisted of braids combined with other materials to fashion the protective gear.

Metals often used include gold, copper, silver, or alloyed copper. Then, its dyed/woven materials were often silk, brocade, cotton, linen, wool, etc. Depending on the type of Do, these sometimes required turtle shells, antlers, horns, ivory, fur, and various types of wood.


Types of Do

The matching suit of armor that came with the  Do defined the name for that specific piece. One example is a suit of armor with a Hotoke Do. It would be a Hotoke Do Gusoku, while the Karuta Tatami Do would be the Karuta Tatai Do Gusoku.

Its design also varied based on the time and preferences of the user. Earlier versions of the breastplate had bigger individual plates, while the later designs used smaller, overlapping ones.

These plates usually had intricate engravings/lacquer work to display the Samurai’s style and rank.

Kozane Do

The original Kozane Do is constructed using lamellar and individual scales called the Kozane. These were used before firearms were introduced in Japanese warfare.



This is an early version of the Do equipped by mounted Samurai of higher rank. It sports a Hon Kozane construction and is often called the rich man’s armor.

It first appeared in the 10th century in the mid and late Heian period. The O-yoroi was widespread in the Genpei War (12th century) when the need for more armor was reached.

Significant aspects of the protective gear were aimed for cavalry archers. It was a heavy piece that did not allow much movement or flexibility, unlike its counterpart, the Do Maru.

For this reason, this Do fell out of favor during the 15th century when warriors preferred infantry tactics.

Do Maru

This is another type of Do that does not feature a hinge. It had an opening on its right side and was constructed with a Hon Kozane.

The Do Maru was equipped by the low-ranking Samurai until the 14th century of the Kamakura period.

Haramaki Do

The Haramaki Do was an early type of armor featuring an opening on its back. This piece was constructed with a Hon Kozane, and later, it was referred to as any Do with a back opening.

These were originally crafted using the same materials as the O-yoroi.

However, they were designed for Ashigaru, while the O-yoroi was meant for mounted warriors. It is worn from the front and then fastened behind with cords.

Hon Kozane Do

These are any Do with small individual scales or Hon Kozane. The latter differed from the Kiritsuke Zane, a common method from the latter part of the 16th century.

It was created by slicing the tops of solid lames to appear like boards made from built-up scales.

Hon Iyozane Do

The Hon Iyozane Do, or Nuinobe Do, is any Do featuring a Hon Iyozane. Compared to the Hon Kozane, this Do overlaps by a fraction of its width along the edges.

For reference, the Hon Kozane overlaps for about half/two-thirds of its width. Since it lacks overlapping,  these are not as sturdy as the previous Do on the list.

Kiritsuke Kozane Do

The False Kozane Do that takes the form of the Kiritsuke Hon Iyozane/Kiritsuke Hon Kozane copies the lamellar armor. But instead of using individual scales, these are actually built using long lames of armor lashed together.

Tosei Do Gusoku

A Do crafted with iron plates (Ita Mono) instead of one Kozane. For this piece, plenty of metals are optimized to cover a larger part of the body.

It became prominent in the 1500 when firearms were introduced, while battle strategies improved. Since many people opted to use this Do, it became mainstream during the period.

The Tosei Do Gusoku usually had more attachments, plus a Kote (gauntlet) and Haidate (thigh guards). It used metal plates that were sewn to the wearer’s underclothes.

Okegawa Do (Tub-sided)

The Okegawa Do featured a tub-like shape which has two types of Okegawa Do. One is the Tatehagi (vertical), and the other is the Yokohagi (horizontal).

Hishinui or Hishi-toji Do

This version of the Japanese cuirass featured rows of conspicuous crossed knots, which are often Okegawa Do. 

Munemenui or Unamenui Do

These chest protectors use a running stitch that runs horizontally across the Do’s surface. The lacing goes along the lame’s surface appearing like dotted lines that parallel the top.

Dangae Do Gusoku

It means step-changing, which is a mix of two or more styles.

Hotoke Do Gusoku

It is a smooth type of Do armor that displays no signs of lames.

Nio Do

These are embossed to appear like an emaciated torso of an old man/monk. This piece takes its name because of it resembles the Buddhist deities with the same name.

There is also a Katahada Nugi Do, which is embossed, but looks more like a half-naked torso.


Yukinoshita or Sendai Do

It is a five-plate or four-hinge (Go Mai) chest armor featuring the Sendai or Yukinoshita motif.

Hatomune Do Gusoku

It can be called the Pigeon-breast chest armor/cuirass or Hatomune Do Gusoku, which was inspired by the peascod armor. This features a sharp center ridge that goes vertically down the front.

Uchidashi Do Gusoku

Uchidashi Do Gusoku are hammered out or embossed on the front.

Nanban Do

This Do was crafted in Europe then gifted/sold to the current Daimyo of that time who favored trading.

Mogami Do

The Mogami Do has five plates and four hinge chest armors with solid lames. Instead of riveted, these are laced with the Sugake Odoshi.

Tatami Do

Tatami Do are known as folding or foldable armor. These are convenient since they are portable and lightweight. Since manufacturing the Tatami Do is inexpensive, these were mass-produced for the Ashigaru.

This type of Do was worn by all Samurai classes. However, those in the higher class had more elaborate armor, while the lower class and retainers had simpler ones.

The following are the different types of Tatami Do used by the ancient Japanese:

Kusari Tatami Do

It is a Japanese chain armor made of iron links formed in different shapes and sizes. When connected to each other, these iron links create pieces of armor. Various patterns are made to suit the wearer.

Karuta Tatami Do

This armor features Karuta or small rectangular or square plates made of leather or iron. The Karuta pieces are linked together and attached on a chainmail.

Kikko Tatami Do

Kikko Tatami Do is similar to the Karuta Tatami Do. However, it features Kikko or small hexagonal plates made of leather or iron instead of square/rectangular ones. These are sewn to a cloth backing or attached to a Kusari or chain armor.

Production of the Japanese Armor Do

When crafting the Do, the most crucial processes include blacksmithing, Odoshi (lacing), and then assembling all necessary components. In addition, other arts such as gold smithing and the like, were important for production.

Great skill, craftsmanship, and dedication are required to complete one protective armor. Why? Because it occasionally required a few years to finish it.

Other than these techniques, extensive labor, as well as expenses, were essential.



The Do was extremely important for defending warriors who bravely faced enemies in battles. It protects the user against blows, slashes, strikes, and other possible attacks from weapons.

Aside from these, the Do breastplate had aesthetic significance to the warriors. The status of a Samurai is reflected by how intricate and elaborately designed their Japanese breastplate was. From there, one could determine rank, and at times, their affiliations.