The Katana: A Traditional Japanese Sword with a Long History

The katana is a traditional Japanese sword. It has a curved, single-edged blade, a round or square guard, and a long handle built for two-handed use. This sword came after the tachi and was used mainly by samurai in feudal Japan. Unlike the tachi, which was worn with the blade facing down, the katana was worn with the edge facing up.

During the Muromachi period, many old tachi swords were shortened. This was done by cutting them at the root and reshaping the blade. These modified blades were turned into what we now know as katana. In Japan, the exact name for the katana is uchigatana, which translates to "striking sword." But in modern usage, the word katana often refers to any single-edged sword, even ones outside Japan.

The term “katana” first showed up in Japanese writing in the Nihon Shoki, which dates back to the year 720. The word itself is made from two parts: kata, which means "one side," and na, which means "blade." This is in contrast to the tsurugi, a sword with a double-edged blade.

A katana is part of the broader nihontō category, which includes all traditional Japanese swords. It stands out with a blade length over 2 shaku - that’s about 60 centimeters or 24 inches. It has a balanced curve, not as dramatic as the older tachi swords.

Some Western sword collectors and martial arts fans also call the katana a dai or daitō. The term daitō means "big sword" and is a general label for any long Japanese sword. So while it's sometimes used for katana, it’s not specific to this type.

In English, both “katana” and “katanas” are used to mean one or more of the swords. Japanese doesn’t have separate words for plural forms, so either version is correct in English writing.

The word katana is pronounced just how it looks: [ka-ta-na]. The Japanese reading of the kanji 刀 is what’s called kun’yomi, and it originally meant any single-edged blade in Chinese. The word even made its way into Portuguese, where it became catana. There, it refers to a large knife or machete.

The modern katana is defined by its size and shape. It has a blade longer than 60.6 centimeters, or roughly 23.86 inches. The blade is curved, slim, and sharp on just one edge. It usually has a circular or square handguard, called a tsuba, and a long handle for two-handed grip.

When a sword is signed, you can often tell if it’s a tachi or katana by looking at the signature, or mei, on the tang, which is the part of the blade hidden in the handle. The signature is engraved on the side that faces outward when the sword is worn. A tachi hangs with the cutting edge down, while a katana sits with the edge facing up. That means the mei will be on opposite sides, depending on the sword type.

 

The Katana’s Role in Japanese Warfare and Society

Western historians often rank the katana as one of the sharpest and most effective cutting weapons in military history. But in Japan’s 16th-century Sengoku period, swords weren’t the main tools of war. Bows (yumi), spears (yari), and early firearms (tanegashima) dominated the battlefield. The katana and tachi were mostly used when enemies got too close for anything else.

As the nature of battle changed, so did the weapons. Large groups of foot soldiers (ashigaru) became the backbone of armies. That change made older weapons like the tachi and naginata less practical. Spears and katanas took their place. These were easier to use in tight formation and quicker to produce and carry.

When Japan entered the Edo period, war slowed down. Long stretches of peace meant the katana took on more meaning beyond combat. It became a symbol of status and discipline. Toward the end of the Edo era, political activists known as shishi often used katanas in armed confrontations. These weren’t battles on open fields but fights in city streets and tight quarters, where a katana’s speed and control gave it an edge.

Katanas also held cultural and spiritual value. Lords (daimyo) gave them as gifts. Shrines accepted them as offerings. Samurai carried them not just for battle, but as proof of rank and loyalty.

 

Sword Periods in Japanese History

Japanese swordmaking has been split into distinct time periods. Each era reflects changes in society, warfare, and craftsmanship.

The Jōkotō period covers ancient blades made before the year 900.

The Kotō period includes swords from about 900 to 1596.

Then comes the Shintō period, spanning 1596 to 1780.

Next is the Shinshintō era, from 1781 to 1876.

Finally, the Gendaitō period starts in 1876 and continues to today.

Each of these periods shows a chance in how swords were made and why they were used. Let’s talk about the Kotō period.

 

Kotō: Old Swords and the Roots of the Katana

The katana evolved from a blade called sasuga, which was a type of short sword or tantō. Foot soldiers in the Kamakura period, between 1185 and 1333, often carried sasuga as a backup. Their main weapon was the long naginata, used for reach in battle. Sasuga gave them something smaller and faster if the fight got too close.

Later, during the Nanboku-chō period, long swords like the ōdachi were common. Sasuga blades got longer too. Eventually, that change in size and shape helped form what we now know as the katana.

Another theory points to the koshigatana, another style of tantō, worn at the waist by higher-ranking samurai. Like the sasuga, the koshigatana may have grown longer and evolved into the katana over time. Both paths could have played a part in shaping the blade’s final form.

The oldest katana still around today is called the Hishizukuri uchigatana. It was made during the Nanbokuchō period and later given to Kasuga Shrine as an offering. This sword stands as a clear example of the katana’s early shape and structure.

The Word “Katana” and Its Early Use

The word “katana” first showed up in writing during the Kamakura period. Back then, it referred to a long sword that wasn’t the same as a tachi. These early mentions of uchigatana and tsubagatana suggest a new style of sword. These were likely made for lower-ranking fighters who needed a simpler and cheaper weapon.

Around 1400, blades started showing signatures on the tang in the katana style. This wasn’t just a trend. It was tied to how samurai had started wearing their swords.

Tachi were worn with the edge facing down, so the signature (mei) was carved on the outward-facing side. But as some warriors began wearing swords with the cutting edge up, like a katana, the old placement for the signature ended up on the wrong side. So swordsmiths started carving the mei on the opposite side to match this new style of wear. That change confirmed that samurai were starting to use their swords in a different way. They weren’t just copying a trend. They were adapting the weapon to better suit real needs.

Japan’s Sword Exports and Global Reach

By the 15th century, Japanese swords had earned a name for themselves outside of Japan. Swordsmiths were making katana that were being sent abroad, especially to Korea and China. Korea, in particular, took note of the blade’s quality.

Korean blacksmiths began traveling to Japan to study how the swords were made. Japanese smiths were also invited to Korea to teach their techniques. One record from June 1, 1430, in Korea’s official Joseon Dynasty records, tells the story of a Korean swordsmith who trained in Japan. He brought a sword back to Korea and gave it to the king. The blade was so well made that it was said to be just as good as a sword from Japan. The smith was rewarded for his skill.

That story shows how much respect Japanese sword craftsmanship had earned. The katana wasn’t just a local weapon anymore. It had become a model for quality, even outside Japan.

The Katana’s Rise as the Main Weapon in Japanese Warfare

In early Japanese warfare, bows (yumi) were the primary weapon. Swords like the tachi and polearms like the naginata were saved for close combat. That changed during the Ōnin War in the late 1400s. This conflict, during the Muromachi period, marked a change in how wars were fought in Japan. It became a full-scale civil war with thousands of foot soldiers, known as ashigaru, drawn from the farming population. These soldiers carried short swords, often shorter than a tachi, and fought in tight infantry lines.

By the Sengoku period, Japan was locked in constant conflict. War expanded, and ashigaru became central to the military. They started using spears (yari), which were handed out by their commanders. Later in the 1500s, the Portuguese introduced firearms known as tanegashima. These guns quickly spread across Japan. Swordsmiths adapted by mass-producing upgraded firearms, which ashigaru also carried.

Guns and spears soon took over the battlefield. Bows were still used, but the traditional tachi and naginata fell out of practical use. They were too bulky and hard to manage in fast, chaotic combat. The katana replaced them because it was lighter, easier to wear, and quicker to draw. The tachi, once a battlefield weapon, became more of a status piece. High-ranking samurai wore it as a sign of their rank and prestige, not for fighting.

The Growth of Katana-Based Swordsmanship

As the katana became more common, new sword skills were developed to match. One major advantage of the katana was how fast it could be drawn and used. This was vital in a time when quick reaction often meant survival. This need gave rise to kenjutsu, a set of fighting techniques that matched the katana’s design.

A key part of this was battōjutsu, the art of drawing the sword and striking in one motion. That practice lives on today in the form of iaido, which teaches smooth, controlled draws. The katana helped make this possible because of how it was worn, through a sash (obi) with the edge facing up. The curve of the blade and its position at the waist meant it could be drawn and used in one clean move. In contrast, the older tachi was worn edge-down and suspended from a belt, making it slower to access.

Mass Production and Export of Japanese Swords

As Japan plunged deeper into large-scale wars in the 15th and 16th centuries, the need for weapons skyrocketed. Swords were made quickly and in high numbers. These cheaper blades were called kazuuchimono. Schools like Bisen and Mino produced them using division of labor to speed things up. These swords weren’t luxury pieces, but they got the job done.

At the same time, Japan started exporting swords at a huge scale. Between the late 1400s and early 1500s, over 200,000 Japanese swords were shipped to China in official trade. The Ming dynasty wanted to limit piracy in the region, and buying up Japanese swords was a way to slow the pirates down. Chinese soldiers studied Japanese sword tactics and created their own versions, like the wodao and miaodao, based on Japanese blades.

Swords Were Reforged as Katana

With changing battle needs and trends, many older swords were altered. Tachi from earlier times were often reshaped into katana. This process is called suriage. The blade was cut at the tang (nakago) to shorten it and refit it for modern use. A famous example is the work of Masamune, a master swordsmith from the Kamakura period. Most of his surviving swords today are katana or tantō, not tachi, because many of his original pieces were reshaped.

The Katana’s Global Reach and Influence

During the 1500s, Japan’s sword exports extended to Southeast Asia. Many katana-style swords were shipped to Thailand, where they were highly valued both as weapons and as works of art. Some of these blades ended up in the collections of the Thai royal family and remain there today.

Between the Sengoku period and the early Edo period, some samurai wore their katana edge-down, mimicking the old tachi style. These swords were called handachi, or "half tachi." They mixed the two styles. The way they were worn was katana-style, pushed through the sash, but the scabbard design followed the older tachi traditions.

Weapons Ownership and Control

During the height of the Sengoku period, weapons weren’t just for the military. Farmers, monks, and townspeople could own swords too. But that changed in 1588. Toyotomi Hideyoshi, a key leader in Japan’s unification, ordered a full-scale sword hunt. His government stripped farmers of their weapons in an effort to prevent rebellion and solidify class divisions. Only the samurai class was allowed to keep swords after that.

Blade Length Over Time

The katana’s length wasn’t fixed. It changed depending on the time period and how it was being used. In the late 1300s and early 1400s, the average blade length was between 70 and 73 centimeters, or about 28 to 29 inches. By the early 1500s, that length dropped closer to 60 centimeters, or 24 inches. This made the blade easier to carry and draw. But by the late 1500s, the length crept back up again to around 73 centimeters. The katana adjusted to the times, matching both function and fighting style.

 

Shintō: The Era of New Japanese Swords After 1596

Japanese swords made after 1596, during the Keichō period of the Azuchi–Momoyama era, are known as shintō, which means "new swords." These blades came after the older kotō swords and are different in both how they were forged and the type of steel used. The change happened for a few reasons.

One major reason was the fall of the Bizen school. It was the largest swordsmith group in Japan at the time, but a massive flood in 1590 wiped it out. After that, the Mino school became more dominant. Around the same time, Toyotomi Hideyoshi had unified most of Japan. With that political unity came a more even distribution of steel, which led to big changes in how swords were made.

Swords from the earlier kotō period, especially the Bizen blades from the Kamakura era, had a cloudy line called midare-utsuri. This misty pattern sat between the temper line (hamon) and the ridge line (shinogi). That feature nearly vanished in shintō blades. The newer swords looked brighter overall, with a more solid, hard appearance. For a long time, no one could recreate the midare-utsuri. It wasn’t until 2014 that Kunihira Kawachi managed to bring it back.

As the violent Sengoku period faded and Japan entered the Azuchi-Momoyama and Edo periods, sword-making evolved. It became more focused on skill, style, and visual appeal. Craftsmanship started to matter as much as cutting ability. During the Edo period, samurai liked swords with glossy lacquered scabbards, silk-wrapped handles, finely detailed handguards (tsuba), and fancy metalwork. Peace across the country meant swords were less about battle and more about ceremony and display.

One major figure in this movement was Umetada Myōjū, who founded the Umetada school. He’s often seen as the father of shintō. His school took sword artistry to a new level. They weren’t just swordsmiths. They were also metalsmiths who engraved blades, designed handguards, reworked old tachi into modern katana (suriage), and added gold inlay for decoration.

At this time, the Tokugawa shogunate set strict rules for samurai. Every samurai had to carry two swords: a long katana and a shorter blade. The shorter one was usually a wakizashi, sometimes a tantō. Together, these formed a pair called a daishō. Only samurai were allowed to wear this pair. It wasn’t just about weapons. It was a status symbol. It showed rank, pride, and honor.

While samurai could wear stylish mounts for their swords every day, there were strict rules for formal occasions. When entering a castle, they had to wear a specific set. The blades had to be in black scabbards, with white ray-skin hilts wrapped in black string. These formal sets were still part of the shintō tradition.

 

Shinshintō: The Revival of Traditional Japanese Sword Craft in the Late Edo Period

By the late 1700s, Japanese sword making had drifted far from its roots. Katana were becoming more about decoration and display than strength or purpose. One swordsmith, Suishinshi Masahide, didn’t like where things were headed. He spoke out against the modern blades of his time, saying they lacked the toughness and power of earlier swords.

Masahide believed the best swords were from the Kamakura to Nanbokuchō periods. These older kotō blades had bold shapes, strong steel, and serious cutting ability. He pushed for a return to that old style of forging. His movement sparked a change in how katana were made. Blades forged under this new approach are called shinshintō, meaning “new-new swords.”

One standout smith from this period was Minamoto Kiyomaro. He earned the nickname “Masamune in Yotsuya” because of his tragic personal life and his rare skill. His swords are still famous today, known for their top-tier craftsmanship. From 2013 to 2014, his work was featured in major exhibits across Japan, and his blades often sell for high prices.

Even now, many still believe that the Kamakura period produced the greatest Japanese swords. This idea isn’t just a matter of opinion. As of the 21st century, most Japanese swords labeled as National Treasures come from that era. Around 80 percent of those treasures were forged during the Kamakura period, and 70 percent of them are tachi, not katana.

Then, in 1853, everything changed again. Commodore Matthew Perry arrived in Japan, and his presence led to the Convention of Kanagawa. That moment threw Japanese society into turmoil. Political tension grew fast. Two sides began to clash: sonnō jōi supporters, who wanted to restore power to the emperor, and sabaku loyalists, who stood by the Tokugawa shogunate.

The activists involved in these fights were called shishi. They weren’t just protesting; they were armed and ready. Many carried swords known as kinnōtō or bakumatsutō. These katana were built for actual combat. They had longer blades - over 90 centimeters, or about 35.4 inches. They were straighter than older swords and had large, sharp tips. That design made them better for stabbing in tight indoor spaces, which was where a lot of fighting happened during that time.

 

Gendaitō: Modern Japanese Swords in the Post-Samurai Era

During the Meiji period, Japan went through major changes. The old samurai class started to fade out, and with it, their long-held privileges. One of the biggest changes came in 1876 with the Haitōrei Edict. This law banned the public carrying of swords, except for a few people like former samurai lords, soldiers, and police officers. That move marked the end of swords as everyday symbols of power and status.

Because of this, swordsmiths had a hard time staying in work. Japan was building a modern army, and there was no need for traditional blades anymore. Many skilled craftsmen had to switch trades. They started making tools, farm gear, and kitchen knives instead of swords.

Still, a few swordsmiths refused to let the tradition die. Two names stand out from this time: Miyamoto Kanenori and Gassan Sadakazu. Both were recognized as Imperial Household Artists, which was a rare honor. Their work helped keep the sword-making craft alive during a time when most of the country had moved on.

Another important figure was Mitsumura Toshimo. He was a businessman who deeply cared about preserving Japan’s sword-making heritage. He supported swordsmiths by commissioning new blades and ordering sword fittings. He wasn’t just interested in the swords themselves. He had a passion for the parts that went with them - the mountings, guards, and fittings. Over the years, he collected around 3,000 sword mountings from the late Edo and Meiji periods.

His efforts helped save parts of the craft that would’ve otherwise disappeared. About 1,200 pieces from his personal collection are now kept at the Nezu Museum, where they remain an important part of Japan’s cultural history.

 

Military Swords in the Meiji and Shōwa Periods

When Japan began military campaigns in China and Russia during the Meiji period, people started paying more attention to swords again. But actual large-scale sword production didn’t pick up until the Shōwa period. Swords made for the military between 1875 and 1945 are known as guntō, which means "military sword" in Japanese.

Before World War II and during the war itself, every Japanese officer had to wear a sword. Some of these were made using traditional techniques. But because the military needed so many, the government brought in blacksmiths who had little to no experience with authentic swordmaking. The proper Japanese steel, called tamahagane, was also in short supply, so other types of steel had to be used. Faster production methods took over. Power hammers replaced hand tools, and oil was used to quench blades instead of water. These changes helped speed things up but moved away from the traditional process.

Swords made during this time using non-traditional methods are called shōwatō. The name comes from Emperor Hirohito’s era, the Shōwa period. In 1937, Japan began stamping the tangs of these swords to tell them apart from real handmade swords. During the war, many older swords were refitted with modern military fittings so they could be carried into battle.

Today, in Japan, shōwatō are not seen as true Japanese swords. They’re not treated the same under the law and can even be seized. Outside Japan, though, many people collect them for their historical value.

Sword Bans and Restrictions After World War II

After the war ended in 1945, Japan banned sword production and martial arts tied to swords. This lasted until 1953. Many blades were taken and destroyed, and swordsmiths lost their main way to make a living. Once the ban was lifted, swordmakers were allowed to work again, but under tight rules.

Swordsmiths in Japan now have to be licensed. They also need to complete a five-year apprenticeship before they can make swords on their own. Even then, each licensed smith can only produce two long swords a month. Every sword must be officially registered with the Japanese government. These rules were put in place to preserve the craft and limit overproduction.

Modern Katanas Outside Japan

In other countries, especially in the West, some swordsmiths make katanas using modern steel like L6 or A2. These swords keep the shape and size of traditional katana, and martial artists use them for iaidō or for cutting drills called tameshigiri. They aren’t made the old-fashioned way, but they serve a purpose for training and practice.

There are also mass-produced katana replicas sold worldwide. These include iaitō, which are dull practice swords, and shinken, which are sharp. Most of these come from China, which now leads the market in katana-style sword manufacturing. The quality and methods used vary a lot.

According to a group in Japan called the Parliamentary Association for the Preservation and Promotion of Japanese Swords, many katana being sold globally today are fakes made in China. A report by the Sankei Shimbun said this is partly because Japanese swordsmiths are only allowed to make 24 swords a year each. That rule helps maintain high quality but limits the supply, opening the door for cheap copies to flood the market.

Efforts to Recreate Legendary Swords

After the Edo period, many swordsmiths tried to bring back the exact style and craftsmanship of Kamakura period swords. Those blades are often seen as the finest in Japanese history. But no one really succeeded until 2014. That year, a master swordsmith named Kunihira Kawachi finally pulled it off.

He won the Masamune Prize, which is the top honor in swordmaking. The award isn’t given out unless someone achieves something truly rare. In the category of tachi and katana, no one had won the prize for 18 years before Kawachi did.

 

Common Katana Blade Types

Katana blades come in several shapes, each designed for different strengths and cutting styles. The most well-known shape is called shinogi-zukuri. This is the standard blade type seen in most katana. It has a strong balance between slicing power and speed. You can spot it by the yokote, a clear line or angle where the main blade meets the tip. This design came about after the Heian period and has been widely used ever since.

Another type is shobu-zukuri. It’s based on the same shape as shinogi-zukuri but without the yokote. Instead of a sharp break between the blade and the point, the cutting edge flows in a smooth curve all the way to the tip. This gives the sword a cleaner look while still keeping a solid cutting edge.

There’s also the kissaki-moroha-zukuri blade, which is less common but easy to recognize. It has a curved shape like a katana, but both edges are sharp, not just one. The tip is symmetrical, giving the sword a distinct look and added piercing strength.

Outside of these main types, other blade styles exist too. These include osoraku-zukuri, which has a large tip section, unokubi-zukuri, shaped like a cormorant’s neck with a narrowed back half, and kammuri-otoshi-zukuri, where the back of the blade is tapered near the tip. Each style affects the weight, balance, and handling of the sword in different ways.

How a Katana Is Forged and Built

The typical katana has some clear physical features that set it apart from other swords. One key part is the cross-sectional shape of the blade, often based on the shinogi-zukuri style. When seen from the side, the blade has a raised ridge line called the shinogi. This runs between the cutting edge and the back of the blade. It gives the sword more strength while keeping the weight low. That ridge is part of what makes a katana so good at cutting without being too heavy.

Another key trait is how the blade and handle are put together. The blade includes a nakago, or tang, which fits into the handle, or tsuka. A small peg called a mekugi holds the blade in place. This connection is secure but also simple enough to take apart when needed.

Traditional katana are made from a special kind of Japanese steel called tamahagane. This steel is made using a unique smelting method that creates multiple layers of steel with different carbon levels. The purpose of layering is to even out the carbon content and get rid of unwanted impurities. Older steel, which has more oxygen, can be cleaned more easily when hammered, and this helps create a much stronger blade.

The swordsmith starts by heating and folding the steel again and again. This process evens out the mix and strengthens the metal. After several rounds of folding and welding, the steel becomes a solid block. That block is then stretched and shaped into a billet, which is the raw form used to craft the final blade.

How the Katana Gets Its Signature Curve and Finish

When the katana blade is first shaped, it’s usually straight or just barely curved. That signature curve people recognize doesn’t happen right away. It comes from a method called differential hardening or differential quenching. This step is where the sword truly takes form.

The process starts with the smith applying a wet clay mixture to the blade. This mixture is different for every sword maker but usually includes clay, water, and sometimes ash, powdered grinding stone, or rust. The process is called tsuchioki. The smith puts a thin layer of this clay on the edge and a thicker coat on the spine and sides. Then, the blade is heated and quenched, usually in water. A few makers use oil, but that’s rare.

This clay coating causes the edge to cool and harden much faster than the spine. That difference in cooling speeds creates two types of steel in one blade. The edge becomes hard and sharp, while the back stays softer and more flexible. That’s also what causes the blade to curve. The uneven cooling makes the edge pull tighter than the spine, giving the katana its natural bend.

When steel with about 0.7 percent carbon gets heated over 750 degrees Celsius, it changes into something called austenite. If it cools quickly, like when it’s dropped in water, it becomes martensite, a very hard form of steel. But if it cools slowly, it turns into a mix of ferrite and pearlite, which are much softer.

This heating and quenching not only shape the blade but also create the hamon, a visible pattern that runs along the side. The hamon shows where the hard steel of the edge meets the softer steel of the spine. You can spot it better after the blade is polished, but it’s not the bright white line people often think it is. That white area comes from a special polishing technique called hadori. The actual hamon is a blurry line inside the white area. You can only really see it by tilting the blade in the light while holding it.

Finishing the Blade: Polishing and Craftsmanship

Once the blade is hardened and curved, it moves on to polishing. This step is critical. A proper polish can take anywhere from one to three weeks. The person doing this job uses a range of polishing stones, each finer than the last. This is called glazing. By the end, the blade has a bright, mirror-like surface. But the back edge, which isn’t sharpened, usually gets a dull finish instead. That matte section helps bring out the hamon and makes the blade’s structure easier to see.

Making a katana is not a one-person job. It takes a team of skilled craftspeople, each focused on one part of the process. The tosho, or swordsmith, is the one who forges the blade. The togishi handles polishing. The kinkōshi or chokinshi makes the metal fittings. The shiroganeshi is in charge of the habaki, the metal collar that sits at the base of the blade. The sayashi builds the wooden scabbard, and the nurishi applies lacquer to it. The tsukamakishi wraps the hilt, and the tsubashi crafts the tsuba, or hand guard.

In the past, before the Muromachi period, swordsmiths and armorers often made the tsuba themselves using leftover metal. But during and after the Muromachi period, that job shifted to specialists. Today, a kinkōshi might also take on the roles of shiroganeshi and tsubashi, depending on the workshop.

 

How the Katana Is Appreciated as Both Weapon and Art

In Japan, the katana has always been more than a weapon. It’s been seen as a work of art, especially when made with great skill. While other cultures often focus on flashy details or decoration, Japanese sword appreciation puts the blade itself at the center. The shape, structure, and fine details of the blade matter more than any ornament or lacquered handle.

When looking at a katana for its beauty, there are three main things people notice first. The most important is the overall shape, called sugata. This includes the curve of the blade, its length and width, the form of the tip, and the shape of the tang. All these parts come together to define the sword’s character.

Next is the pattern in the steel surface, known as hada or jigane. This pattern shows up from how the metal was folded and forged over and over. It can look like tree rings, bark, or even fingerprints. These marks are signs of expert craftsmanship and can’t be faked.

Then there’s the hamon. That’s the hazy line that runs along the cutting edge, created when the sword is hardened through quenching. The exact shape of the hamon and the crystal formations inside it are a big part of how a blade is judged. These crystals form as tiny bright particles, which fall into two types. The first is nie, made up of larger, more visible particles. The second is nioi, a finer mist-like texture. Some look like stars scattered along the blade, while others appear like fog near the edge. You usually can’t see these features clearly unless you turn the blade around in the light.

There are other elements collectors look at too. A swordsmith’s signature, often carved on the tang, matters a lot. There may also be a file pattern etched into the tang. Some blades even have decorative carvings known as horimono. All of this adds to the blade’s value and story.

One family in particular, the Hon'ami clan, was known as the top authority on judging Japanese swords. They focused on these exact qualities when rating swords, not just for quality but also for who made them and when. Today, sword experts do the same. They use these artistic traits to identify which school or maker forged the sword, and which period it came from.

Most museums in Japan keep the blade and its fittings separate when they’re on display. This setup puts all the focus on the blade. One good example is the Nagoya Japanese Sword Museum, called Nagoya Touken World. It’s one of the biggest sword museums in Japan, and they even post separate videos online - one showing the blade alone, and another showing just the fittings.

 

How Japanese Swords and Swordsmiths Are Ranked Through History

In Japan, sword appraisal has always carried weight. Over the centuries, different systems have been used to rate Japanese swords and their makers. Some of these rankings are still respected today.

Back in 1719, Tokugawa Yoshimune, the eighth shogun of the Tokugawa shogunate, ordered Hon'ami Kōchū, a well-known sword appraiser, to document the swords owned by daimyo across the country. The result was a record called Kyōhō Meibutsu Chō. It listed 249 valuable swords, and later, 25 more were added. The list also mentioned 81 swords that had been lost in fires. These prized blades were called Meibutsu, which means "noted objects." Swords made it into the book based on artistry, origin, and legend.

Among those listed, 59 were made by Masamune, 34 by Awataguchi Yoshimitsu, and 22 by Go Yoshihiro. These three were placed in a class of their own. But not every rare blade was recorded. Some daimyo kept swords hidden, afraid the government might take them. That’s why even major blades like Daihannya Nagamitsu and Yamatorige - now recognized as National Treasures - didn't make it into the book.

In 1797, Yamada Asaemon V, the shogunate’s official sword tester and executioner, published a book called Kaiho Kenjaku. He ranked swords by how well they could cut. This book listed 228 swordsmiths whose blades were known as Wazamono, meaning “cutting swords.” The highest category was Saijō Ō Wazamono, or “supreme grade cutting swords,” and at first, it included 12 names. Later versions of the book added more. By 1830, the updated version called Kokon Kajibiko included 15 top-rated smiths.

Nagasone Kotetsu was one of the highest-ranked smiths. His swords became so popular that many fakes were made. Oddly enough, the three famous smiths from the Kyōhō Meibutsu Chō weren’t listed in Yamada’s book. Neither was Muramasa, despite his reputation for forging powerful blades. There are several possible reasons for this. Yamada may have avoided mentioning blades owned by daimyo or feared overstepping the shogun's authority. He may also have avoided Muramasa due to the dark legends linked to his swords.

Today, Japan protects swords of great value under the Law for the Protection of Cultural Properties. Blades judged to hold historical importance are labeled as Important Cultural Properties, or Jūyō Bunkazai. Some swords, due to their exceptional status, are declared National Treasures, or Kokuhō. Under an older law from 1930, now repealed, some swords were listed as Important Art Objects, or Jūyō Bijutsuhin, which is the next highest status.

There’s also an independent group called The Society for Preservation of Japanese Art Swords. It gives top ratings to especially valuable swords, with the highest being Special Important Sword, or Tokubetsu Juyo Token. These are treated on the same level as Important Art Objects. Swords owned by the Imperial family aren’t given official cultural property status, because they’re outside the law’s jurisdiction. Still, many of those swords are considered National Treasure-level and are known as Gyobutsu.

As for swordsmiths, several official systems rank them. From 1890 to 1947, two smiths were named Imperial Household Artists by the Japanese government. Since 1955, six others have been recognized as Living National Treasures. The same sword preservation society that rates blades also honors top smiths. Since 1958, 39 swordsmiths have been named Mukansa, meaning “above appraisal.” That title means they are masters, beyond the need for judging.

The best sword made in any year is awarded the Masamune Prize, named after one of Japan’s most famous smiths. Since the prize was introduced in 1961, only eight smiths have received it. Of those, four men stood out: Masamine Sumitani, Akitsugu Amata, and Toshihira Osumi each won the award three times. Sadakazu Gassan II won it twice. All four were both Living National Treasures and Mukansa, putting them at the peak of the craft.

 

Katana in Martial Arts Practice

Samurai didn’t just carry the katana into war. They also trained with it as part of their martial arts routines. Today, the katana still plays a role in many modern Japanese martial arts. You’ll see it used in aikido, iaijutsu, battōjutsu, iaidō, kenjutsu, kendō, ninjutsu, and in classical schools like Tenshin Shōden Katori Shintō-ryū and Shinkendo.

That said, the swords used in practice are usually not sharp. Most martial artists use blunt-edged swords called iaitō, or wooden ones known as bokken. These are meant to prevent serious injuries during training. Live blades, or sharp katana, are mostly reserved for tameshigiri. That’s the practice of test-cutting, usually on bamboo stalks or rolled tatami mats.

If you don’t care for a katana properly, it can get ruined. Storage and maintenance are serious business. The sword should lie flat in its scabbard, edge up, with the curve facing down. This keeps the blade from dulling. It also needs to be oiled, powdered, and polished often. Skin oils from your hands can eat through the metal and cause rust. The go-to oil for upkeep is chōji oil. It’s made mostly of mineral oil, with a small amount of clove oil to mask the scent.

If you’re storing the katana for a while, you can’t just forget about it. You’ve got to check on it now and then. Rust and mold can build up, especially if there’s moisture. The salts from the polishing oil can even feed mold, so airing out the sword is a good idea.

Katana have also made a name for themselves in world records. Iaido master Isao Machii holds several Guinness World Records. He cut the most straw mats in a single strike, made the fastest 1,000 cuts with a sword, sliced the most mats in three minutes, and even cut a tennis ball moving at 708 kilometers per hour. Another record was set by Agisilaos Vesexidis from Greece. He landed 73 sword cuts in just one minute during a tameshigiri session in 2016.

 

Laws Around Katana Ownership and Trade

Republic of Ireland

In Ireland, owning a katana is illegal if it was made after 1953 and doesn’t follow traditional crafting methods. This rule falls under the Firearms and Offensive Weapons Act of 1990. The change came in with the 2009 amendment, which tightened laws around weapons seen as dangerous.

United Kingdom

The UK also cracked down on katana ownership. In April 2008, the British government added curved swords with blades longer than 50 centimeters to the Offensive Weapons Order. This measure was introduced after samurai swords were linked to over 80 violent attacks and four deaths over four years.

Under the law, anyone caught breaking the ban could face up to six months in jail and a fine of up to £5,000. But there are exceptions. Martial artists, historical performers, and collectors can still legally own these swords. You can also buy or keep a katana if it was made in Japan before 1954 or was made using traditional techniques. The sword is also legal if it’s used strictly for martial arts. This rule covers England, Wales, Scotland, and Northern Ireland.

Later that same year, in August 2008, the ban was eased a bit. The update made it legal to buy and own traditional, hand-forged katana without needing a special license.

 

Tsurugi: The Ancient Straight Sword of Japan

The tsurugi, also called ken in Japanese, is an old type of sword. It’s straight and double-edged, unlike the curved, single-edged katana or tachi. Outside Japan, the word tsurugi usually refers to this specific kind of ancient blade. But in Japanese, tsurugi or ken can mean any long, double-edged sword, even ones from other cultures.

What sets the tsurugi apart is its design. It has two sharp edges, one on each side. Swords like the katana, wakizashi, tachi, and ōdachi only have one cutting edge on one side. The tsurugi is built to cut from both directions, similar to the Chinese jian, which in Japanese is called chūgokuken.

The earliest example of a sword found in Japan is actually a bronze dagger from China. It dates back to around 800 BCE, during the Yayoi period, which spanned from 1000 BCE to 300 CE. Around 200 BCE, Japan began making its own bronze tsurugi. Many of these have been found at various archaeological sites, which suggests they were made in large numbers.

These early tsurugi weren’t always used in battle. Most were made for rituals and religious use. The Yayoi period marked the switch from bronze tools to iron. Iron tsurugi didn’t appear until later, around the 5th century, during the Kofun period. Sword forging continued into the 9th century, during the Heian period.

After the 10th century, the shape of Japanese swords started to change. The curved tachi was developed, and that eventually led to the creation of the katana. As curved swords became more common, the straight tsurugi stopped being used in combat. From then on, tsurugi were only made for spiritual reasons. They became offerings to Buddhist temples and Shinto shrines instead of weapons for war.

One famous tsurugi from the Heian period is kept at Kongō-ji and stored at the Kyoto National Museum. It was made to look like the sword held by Fudō Myōō, a Buddhist deity. The hilt of the sword is shaped like a vajra, a tool used in Buddhist rituals.

Today, the tsurugi is mostly tied to Japan’s distant past. It’s also linked to myths and ancient stories. While it’s no longer part of modern martial arts or daily use, it still holds a strong place in Japanese tradition and religion.

 

Kusanagi no Tsurugi: The Sacred Grass-Cutting Sword of Japan

Kusanagi no Tsurugi is one of the most famous legendary swords in Japan. It's also one of the Three Imperial Regalia, the sacred treasures tied to the Japanese throne. At first, it was called Ame no Murakumo no Tsurugi, which means “Heavenly Sword of Gathering Clouds.” Later, the name changed to Kusanagi no Tsurugi, meaning “Grass-Cutting Sword.” In Japanese mythology, this blade stands for bravery.

The story of this sword begins deep in Japanese folklore. According to the Kojiki, a book of myths, the storm god Susanoo once met a heartbroken family of land gods in Izumo. The head of the family, Ashinazuchi, told Susanoo that an eight-headed serpent called Yamata no Orochi had already devoured seven of his eight daughters. Now the beast was coming for the last one, Kushinada-hime.

Susanoo decided to face the monster. But first, he asked to marry Kushinada-hime. The father agreed. To keep her safe, Susanoo turned her into a comb and kept her with him during the fight. He came up with a plan.

He had eight barrels of sake made and placed each one behind a gate in a fence. The serpent came and put one head through each gate to drink. Once the monster was distracted, Susanoo attacked. He used a sword named Worochi no Ara-masa to chop off each head. Then he cut into the tails. In the fourth tail, he found a blade inside the serpent’s body. He named it Ame no Murakumo no Tsurugi. He offered it to the sun goddess Amaterasu to make peace between them. According to the Nihon Shoki, another ancient text, the sword was delivered by Ame no Fuyukinu. Even today, this moment is honored at Hinomisaki Shrine.

Generations later, during the time of Emperor Keikō, the sword was given to the warrior Yamato Takeru. His aunt, Yamatohime no Mikoto, who served at Ise Shrine, gave him two powerful gifts for protection. One of them was this sacred sword.

Yamato Takeru later went on a hunting trip, where a traitorous warlord set a trap. The warlord had him lured into tall grass and then ordered his men to shoot flaming arrows to set the field on fire. They also killed Takeru’s horse to stop him from escaping. Trapped, he used the sword to slash the grass and keep the fire from spreading toward him. While doing that, he discovered the sword could control the wind. Swinging it in different directions changed the way the flames moved. Using fire strikers, the second gift from his aunt, he started a new fire and used the sword’s power to push the blaze toward the warlord and his men. It worked. He survived. After that, he renamed the sword Kusanagi no Tsurugi to mark the moment he cut through the grass and won his life back.

Later in life, he got married. But he eventually died in battle against another creature. He left the sword behind, ignoring his wife’s warning to take it with him.

Today, the real Kusanagi sword remains hidden. Because of its sacred status in Shinto tradition, no one is allowed to see it. We don’t know what it actually looks like or what condition it’s in. But it was last seen (still wrapped in packages) during Emperor Naruhito’s ascension in 2019. Alongside it were the Yasakani no Magatama jewel, the Imperial Seal, and the State Seal.

Replicas of Kusanagi have existed since at least the 9th century. The original sword is said to be kept at Atsuta Shrine in Nagoya. Scholars say a 12th-century replica, stored in the Imperial Palace, is used during official events like coronation ceremonies. That’s probably because the original is too fragile to be handled.

At these ceremonies, the sword is always boxed and carried by a chamberlain. It's called Hi no Omashi no Gyoken, which means “sword of the throne of the daytime.” This ceremonial sword has changed over the years. Right now, two tachi blades made in the Kamakura period by swordsmiths Nagamitsu and Yukihira are used in its place. The Imperial Household Agency manages these and many other swords owned by the Imperial Family. One of the most famous among them is Onimaru, one of the Tenka-Goken, or the Five Swords Under Heaven.

The Crown Prince has his own sacred swords. Two of them are Tsubokiri no Gyoken and Yukihira Gyoken. The Tsubokiri sword means “sword that cut a pot.” It is passed from emperor to crown prince as a symbol of succession. It first appeared when Emperor Uda gave it to Emperor Daigo in 893. The current version is the second-generation sword, made during the late Heian period.

The Yukihira sword is a tachi made by the swordsmith Yukihira in the Kamakura era. The Crown Prince receives it before his inauguration and wears it during many formal events. One exception is the Niiname-sai festival. This Yukihira sword is different from the emperor’s Hi no Omashi no Gyoken, even though they were made by the same smith. Each sword holds its own place in tradition.