Japanese armour evolved over the centuries to adapt to various fighting styles. It provided effective protection and was distinguished by its high level of craftsmanship and precision. The display case in front of you contains individual pieces of samurai armour. They do not form a single set, but come from different ones. Full suits of armour can be seen in display cases located in the central part of the exhibition. Here, the pieces are arranged to resemble the human body, making it easier to identify the body parts they protected. The diagram of the armour on the left-hand side of the display case can also help with orientation. The drawers contain further examples of the finest Japanese craftsmanship.
The development of Japanese armour began with the keikō, which consisted of numerous small, interconnected iron plates called lamellae. From the Heian period onwards, more advanced armour began to emerge, such as the ō-yoroi. This type of armour featured a dō cuirass made up of numerous iron or leather lamellae coated with multiple layers of lacquer. These were connected by leather cords to create overlapping rows, which were then tied together with silk cords called odoshi, forming larger plates. The breastplate was often covered with printed leather to prevent the bowstring from snagging on the plates. The dō was extended with additional rows of lamellae to protect the hips (kusazuri).
As a warrior armed with a bow and arrows could not protect themself with a portable shield, the armour was equipped with large protective plates (ō-sode), which were attached to the shoulders and were similar in design to a cuirass. These plates acted as a shield and were intended to protect against attacks from the side. The armour was complemented by additional pieces: arm protectors made of cloth and iron plates, greaves, and a throat protector.
From the mid-Heian period onwards, another type of armour emerged: the dō-maru. Like the kozane, it was made of lamellar panels, but it was smaller in size. Its design and light weight made it popular among infantrymen, as it allowed considerable freedom of movement.
Further adjustments to armour were prompted by the intense fighting between samurai clans during the Sengoku period, when armies of thousands of warriors faced each other in battle. Armour was intended to be practical, quick, and easy to produce, so various modifications were introduced. Instead of individual lamellae, entire plates (itazane) were used, and the lacing was simplified; sometimes, the plates were joined with rivets. Hinges were also added to the left side of the cuirass to make it easier to put on. Together with the cuirass, the arm protectors, hip guards, greaves, and shoulder guards formed a type of armour known as tōsei gusoku.
During the Azuchi–Momoyama period, the use of firearms became widespread. This resulted in the creation of a new type of cuirass called the nimai-dō, which featured a double-plate design. This consisted of a breastplate and a backplate, each made of a single plate.
During the Edo period (1603–1868), Japan experienced a time of peace and isolation. As a result, armour lost its original purpose, and its protective function faded into the background. It was primarily used for ceremonial purposes. The daimyō (great feudal lords) and their entourage wore sumptuous armour on annual journeys ordered by the shogunate. This was designed according to the preferences of those who commissioned it, resulting in a wide variety of cuirass shapes and types inspired by earlier models. To ensure a lightweight design, many components were made of leather. Original components from older pieces were sometimes used as well.
Following Japan’s opening to international contact in 1854, and during the Meiji period (1868–1912), many pieces of armour left the Japanese mainland and became part of private and museum collections around the world.