Since the Tensho period (1573-92) of the Warring States period, the length of the tachi was from 2 shaku 2 sun to 2 shaku 3 or 4 sun at its longest. Incidentally, although it varied depending on the time and region, the average height of a Japanese male until the early part of the Meiji period was less than 160 cm (5 shaku 3 sun). According to the Tai­heiki, the tachi of Nawa Nagatoshi was 4 shaku 3 sun. Saji Magozaburo of Tanba carried a tachi of 5 shaku 3 sun. In the time of Emperor Gomurakami, Wada Masatomo's tachi was 4 shaku 5 sun, and it is said that Fujiwara no Yasunaga drew a tachi of 4 shaku sun. Tsumaga Nagamune carried a tachi of 5 shaku 3 sun. In the time of the battle of the Fuefuki Pass, Yazu Kojiro had a tachi of 6 shaku 3 sun. Akamatsu Ujinori carried a tachi of 5 shaku 7 sun. The sword of Togashi Masachika appears in the tales of storytellers as 9 shaku 3 sun.

The Ninja sword had a blade length of 1 shaku 6 to 7 sun. In the Tokugawa period, a blade longer than 2 shaku was called a katana. Up to 1 shaku 9 sun was called an o-wakizashi, up to 1 shaku 7 sun was called a chu-wakizashi, and up to 9 sun 9 bu was called a sho-wakizashi. The uchi-gatana that began to appear from the Muromachi period were initially 1 shaku 4 sun, but towards the end of the period went from shaku 7 or 8 sun to 2 shaku in length.

With the daito and shoto (a pair of long and short swords), the long sword is sometimes made into a naginata or yari, and the long and short swords are used together as a pair. The short sword was also effective when used in confined spaces against multiple enemies. There is a prov­erb: "The short sword can be used as a long sword and the long sword as a short sword." 

Real common sense means, when in a fight, look with 'extraordi­nary eyes' (kime). Kime are also an example of "the eyes of god" (shingan); when in combat, this becomes kaname (another reading of shingan), also meaning the 'key' or 'main point,' said to be a very important insight. The 'key' to the incident in which Nasu no Yoi­chi played a crucial role for the Genji clan in defeating the Heike clan is contained in this idea. Yoichi was a famous archer who hit the ceremo­nial war fan of the invading Heike fleet at sea with an impossible shot, providing a symbolic prelude to the defeat that awaited them. 

When you think of using a weapon you are at once enslaved by it. It is important to consider not carrying a sword, not wielding a stick, but using what is available at the time as a weapon. Anything can become a weapon. Look at a thing's advantages and disadvantages as a weapon or at armor, shields, and horses-anything natural or manmade can be used as a weapon. 

"The way of the samurai is found in death." Time passes, seasons continue to change-the four seasons, shiki, phonetically share the same sounds as the timing of death, shiki; reminding us of the cyclic properties of life and death.

If you unravel the phrase "ni no tachi" (usually referring to the idea of two strikes, where the first is a setup for the second) into a first and second sword, you find the small and large swords of the daisho and the use of two swords in combination. You can also see that nito (two swords used together) can mean nito (two fights). The ni no tachi of fighting in armor is the kukan through which one enters the world of fighting; it is a method of thrusting through and entering the defences of an opponent. In the case that you and the opponent are not wearing armor, ni no tachi naturally changes. Two swords then become 'with sword' and 'without sword,' also 'serious' (shinken) or 'real sword' (shinken).

The sword, naginata, and yari change according to the times. In the secret scrolls of the Shinkage-ryu, Tengusho Hiden no Maki are the names of illustrations of techniques-Ransho, Kokyoku, Unsetsu, and Denko-and pictures of samurai using long and short :swords. Someone lacking knowl­edge in bufu would undoubtedly recall the image of the long and short swords being used in Miyamoto Musashi's Nito-ryu. Masters like Koizumi.lsenokami would probably have derided a Bugeisha with such a limited sense: they'd have explained that in such a picture, it is essential that the figure have a tachi in one hand, and a yari, naginata, or nagamaki in the other; explaining that it was a secret meaning. Thus, the picture Tengusho Hiden no Maki has a secret meaning, and people who are not familiar with the period of fighting with a tachi can never truly understand. The point is that the kodachi is not just a kodachi-a yoroidoshi (dagger), a spearhead, the blade of a naginata, and unarmed combat all have the same role; they are all used for the same purpose and are interchangeable. I urge you to see this as a fight scene depicting koteki ryoda of juppo sessho.

To the people of the Empire of Japan, the sword has a significance so profound as to be almost incomprehensible to people of other lands. Part of the Imperial Regalia (sanshu no jingi) the possesion of which is a necessary prerequisite for ruling our country, it signifies courage and power, characteristics much admired by the people of this nation. Since the earliest times, a fine sword has been considered a most appropriate offering for an act of religious devotion, combining as it does in the minds of the Japanese people, the qualities of rarity and great value. Add to this its ability to destroy evil which gives it a stainless purity, and you have literally a gift fit for the gods.

For families of the Samurai caste, fine swords were heirlooms of the greatest possible value, to be used during one's lifetime and passed on with honour to one's heirs. Some fine swords that have been handed down through countless generations of Japan's oldest families are literally national treasures, as is the case with the "Kogarasu-Maru" (little crow) made by Amakuni some time in the eighth century A.D. that was originally a treasure of the great Heike clan. This, together with the "Ama no Murakumo no Tsurugi" (gathering clouds of heaven sword), which forms part of the Imperial Regalia, are now in the care of the Atsuta Shrine.

Some swords are even considered to have particular traits or characteristics. Swords by the brilliant but demented smith Muramasa Senzo while of the very highest quality, are thought to be thirsty for blood and capable of driving their owners to acts of violence.

Blades by certain other smiths are thought to bring happiness and prosperity. Suffice it to say that to the Japanese Nation, the sword has been an object of spiritual, religious and national significance since time immemorial.