Jirinden (5) Originally the length of the blade in the daisho is not decided.
「Daisho-tō wa motoyori sunshaku no sadame nashi」（Heishū Jirinden Vol.1, Tōryū iai katana sunshaku)
“There is essentially no rule regarding the length of the long and short swords.“
Properly speaking there no established measurement regarding the length of the katana. As long as one makes use of a sword that is appropriate to one’s height, weight and physical characteristics, (any length) is fine. It is good if the tsuba covers the fist so a round shape is said to be appropriate.
In a poem we find the following verse:「Onore o ba kagame, katana nomi wa sorase. Gyōsa wa kaku ni tsuba wa marokare」
“Crouching the body, only the katana extends in a curve. Making angles in movement and a round tsuba is good. “
“Making angles in movement” is when the opponent attacks, we receive it according to the angles of a triangle.
Note – The height of men during the Edo era is estimated to have been the lowest in Japanese history at 155 ~ 157cm. Although it is said that the typical length of the katana during this period was from 2 shaku 3 sun to 3 sun 5 bu (70.6 ~ 71.2 cm), there are many short blades of 2 shaku 1 sun 5 bu in the “Higo koshirae” style used in Hōki-ryū iai remaining. This is said to be because when cutting with one hand in iai, the kissaki extends approximately 8 or 9 sun (24 to 27 cm) further than during a two handed cut. Since one can draw a shorter sword more quickly it is said to be advantageous in iai where one instant determines victory or defeat. In modern times, there is a tendency to use swords longer than in those days because of the training in saya-biki (pulling the sword sheath back during the draw).
[Bu, Sun, Shaku: Japanese units that are respectively 0.3, 3.03 and 30.3 cm]
(Presented by: Yuji Wada, Costantino Brandozzi, Rennis Buchner)