Many people believe that the Japanese sword blade has only one specific design; however, the Japanese sword has undergone significant changes in shape over the centuries. In many cases knowledge of these changes in shape (sugata) can be an aid in identifying the period of the blade. Some of the changes were the result of changes in battle tactics, type of armor and/or simply changes in style dictated by the fashion of the day.

The earliest blades (those prior to about 900 AD - pre-Heian period or Jokoto sword period) that are commonly recognizable as Japanese are of the kiriha-zukuri type: straight flat blades with chisel type edges and kamasu kissaki (chisel shaped points) or hira-zukuri type: straight flat blades with curved kissaki, some were double edged. The earliest of these swords had large ring shaped pommels. Blades of these styles are referred to as "chokuto" swords. These styles of swords were probably influenced by the Chinese blades of the period making their way to Japan via the Korean peninsula. Chokuto style blades were made in later times, but mainly as temple offering swords.

Kissaki moroha-zukuri tachi were also made about this time, circa 700-800 AD. Kissaki moroha-zukuri blades have a curved shinogi-zukuri blade with a sharpened kissaki extending back about one third to one half the length of the mune. The most famous of this style is the Kogarasu-Maru (Little Crow) Tachi made around 900 AD and marks the beginning of the Koto sword period. Kogarasu style blades of all sizes were made throughout Japanese history.

The earliest single edged shinogi-zukuri tachi (those with ridge lines) from the late Heian period were basically cavalry sabers - long blades normally over 30 inches in length with considerable koshi-sori (most of the curvature being near the bottom part of the blade). These blades had significant taper (funbari) from the ha-machi to the yokote and ko-kissaki (small points). The blades were quite narrow. Many of the blades of this general period found today have been polished dozens of times and may have little temperline (hamon) remaining on the blade or kissaki. In some cases this is acceptable to collectors for blades of this extremely early vintage.

By the early Kamakura period, tachi had become more robust. The blades were somewhat wider with less funbari, but retained the ko-kissaki. The sori also was somewhat less tending to move out to the middle of the blade (tori-sori). During the middle Kamakura tachi had become very stout with much less taper and had ikubi-kissaki (short stubby points).

The most common shape of the Japanese sword that is seen today first appears during the mid-Kamakura. These blades are somewhat shorter than those of earlier times, with less taper, less sori and chu-kissaki (medium size points).

During the Nambokucho period, blades became quite flamboyant with large wide blades, little funbari or sori and o-kissaki (large points). Many hira-zukuri blades (those without shinoji) were also made in this period as were some chokuto type revivals. . No-dachi, shouldering swords, with blades in excess of 50 inches, were made during this period; however, these proved to be too unwieldy and the style was soon abandoned.

A major change in blade style occured in the early Muromachi period as a result of a shift from cavalry to infantry tactics. The katana is born. The early katana were shortened tachi and have the shape of earlier Kamakura blades, but shorter. The shorter blades facilitated the draw from the edge up katana mounts by samurai on foot.

The Muromachi katana is the classic style blade associated with Japanese swords today. It is a blade between 27-30 inches in length with moderate saki sori, little funbari and chu-kissaki. Other changes occur in the late Muromachi and Momoyama eras, some blades are made wider and stouter with slightly larger kissaki. These changes are difficult for most people to see without direct side-by-side comparison of the blades.

As Japan entered its 250 year long period of peace, the Edo period, the sword also undergoes changes which mark the end of the Koto sword era and the beginning of the Shinto sword era.

While there were variations in shape within the Shinto period, the classic style is that of the Kanbun era (mid 1600's). Blades are made in katana length, circa 26-29 inches, but stouter and with very little curvature and chu-kissaki. Kanbun style blades are nearly straight and quite robust. Many swords of this era are found in collections today.

By the late Edo period, sword making was in decline due to the decreased demand for swords in a country at peace. Many were made more for show than combat having wild, flamboyant hamon and intricate horimono (carvings). Some scholars consider this a period of decadence for the Japanese sword.

When ever extremes appear there is usually a reverse trend to correct the extreme. This is the case in the late Edo period (circa 1780) and marks the beginning of the Shinshinto sword period. The swordsmith Suishinshi Masahide is generally credited with leading a rival of sword making, promoting a return to the styles and methods of the Koto period. During the Shinshinto era swords of all styles are made as copies of Koto blades, but most are copies of shortened tachi blades of the mid to late Muromachi era. Some Kogarasu revivals were made during the Shinshinto period.

With the opening of Japan to the West by Perry in the mid Nineteenth Century and the Meiji Restoration, the traditional Japanese sword nearly ceases to exist. The Meiji Emperor bans the wearing of swords and abolishes the samurai class. Swords after 1876 can not properly be called samurai swords as there were no samurai after that date. This also marks the first large exodus of Japanese swords to the West with many of the largest early English and American collections being assembled during this time. Few traditional swords are made except for special occasions or temple dedications as the Japanese started adopting western style cavalry sabers which were machine made. It is not until the 1930's with the period of Japanese expansion into other parts of Asia that swords of the classic style are again made.

The Showa Era sees a great variety in quality of sword production, from traditionally made Nihonto (gendai blades) to bar stock, machine made swords (Showato) with all variations in between. Most blades are made to a military standard with blades between 25-28 inches in length, having only slight sori, almost no taper (funbari)and chu-kissaki (medium points). The student of the Japanese sword must learn to distinguish between non-traditionally made swords and true gendai blades. While non-traditional blades are of historical interest to militaria collectors and make perfectly fine swords for martial arts use, they are of little interest to collectors of Nihonto. The great variation in methods of production during the Showa Era makes this an area of much needed research.

It is important to remember that the changes in sword shapes did not occur instantaneously. Rather the changes were trends which took, in most cases, many years to develop, therefore numerous variations and intermediate styles are found.

NOTES: The graphics in this article are not proportionate to each other.
They are intended to depict the basic shapes only.

The text of this article was used in the March 1999 issue of Sword Forum Magazine Online.