Shinai

A shinai (竹刀) is a Japanese sword typically made of bamboo used for practice and competition in kendō.

The modern shinai, with four slats of bamboo, is generally credited to Nakanishi Chuzo Tsugutate (died 1801) of Nakanishi-ha Ittō-ryū.

Due to its lighter weight compared to a bokken or a metal katana, a shinai can be wielded in a fashion that allows quicker strikes than would be practicable with a heavier sword.

[4] The word "shinai" is derived from the verb shinau (撓う), meaning "to bend, to flex", and was originally short for shinai-take (flexible bamboo).

Specifications for shinai used in kendō competitions that follow the International Kendo Federation (FIK) rules are below.

A shinai should not be confused with a bokutō, which has a much more similar shape and length to a Japanese sword and is made from a single piece of wood.

The shinai comprises four slats known as take (竹), which are held together by three leather fittings: a hilt (tsuka), or handle wrapping (tsuka-gawa (柄皮)); a fitting at the tip (saki-gawa (先皮)) and a leather strip (naka-yui (中結)) that binds the four slats.

This holds the slats together and also marks the proper kendo striking portion of the shinai, or datotsu-bu (打突部).

The shinai is useful as a practice sword to simulate the weight and feel of a katana or bokken without injuring the user or the target.

As a result of this lack of rigidity, along with the relative innocuous nature of bamboo vs razor-sharp steel, the impacted area is less damaged and may experience only bruising, rather than life-threatening deep cuts or puncture wounds, even with strong and forceful strikes.

Some instructors require the base (kashira) of the handle (tsuka) on the floor and the tip (kissaki) leaning against the wall.

In kendo, the shinai is treated in the same way as a edged or bladed weapon, like an actual metal sword, and competitors are trained to think of it as a dangerous instrument if misused.

In Shinkage-ryū, the sleeve is lacquered Kamakura Red, and rather than covering the entire length, is tied off at the non-split end.