Sai (釵) is the Ryukyu name for a traditional Okinawan weapon also used in India, China, Indonesia, Malaysia, and Thailand. Its form is essentially composed of a kind of rounded, pointed stick with two long, unsharpened projections (tsuba) attached to the handle.
The end of the handle is referred to as the knuckle puller. The sai are constructed in various shapes: traditional ones are rounded, while some reproductions have adopted an octagon in the central rostrum.
The tsuba are traditionally symmetrical, however, the sai called manji or Matayoshi-sai, developed by Shinko Matayoshi, employs two tsuba opposite each other.
The sai is believed to have always been a weapon, although some speculate it originated as an agricultural tool used to measure stalks, plow fields, plant rice, or as stops for wagon wheels, although evidence of these uses is limited.
The sai is known to have been used in other parts of Asia prior to its arrival in Okinawa. The most recent evidence would lead it to an Indonesian origin.
In Malay, the sai is known as chabang (also spelled cabang/tjabang, with the meaning of "branch") and is thought to be derived from the Indian trident. Through trade, the chabang spread through the rest of Indochina and may have reached Okinawa from one or more of these places simultaneously.
In Chinese martial arts, this weapon is known by the name Tiěchǐ (铁尺) and is particularly used by the Zhuang ethnic group of Guangxi.
The usefulness of the sai as a weapon is conferred by its peculiar shape. With the right skill, it can be used against a long sword by trapping its blade with tsuba, in the same way that "main gauche" daggers were used in Western fencing.
There are many different ways to wield this weapon with the hands, giving it the versatility to be used both lethally and non-lethally.
The sai is primarily used as an impact weapon or for quick point strikes to the solar plexus. The sai also has many defensive uses to block other weapons.
One way to hold it is to grip the handle with all fingers and anchor the thumbs in the area between the tsuba and the main stem. This allows you to quickly and effortlessly change between the long front and blunt back.
Shifting is done by putting pressure in the thumbs and rotating the sai until it is fully turned and the index finger is aligned with the handle. The sai is generally easier to handle in this position.
The fist-puller is used to concentrate the force of a punch, while with the long part you can put it towards the enemy, as protection for forearm strikes or to strike as with a normal dagger.
You can keep the index finger extended and aligned with the central handle whether the knuckle puller is up or down.
The finger can stand straight or slightly bent. The other fingers are held on the main stem and the thumb supports the tsuba.
The grips described above highlight the versatility of this implement as both an offensive and defensive weapon. Both grips facilitate its exchange between the point and the knuckle puller while the sai is held with a secure grip.
The sai is usually taught using a pair - holding one in each hand. In the United States a popular style is Yamanni Ryu. There are 5 common kata used in instruction, including two kihon.
The style includes a variety of parries, dodges, strikes, and holds against attackers from all directions and height levels.
The use of the point, knuckle, and middle bar is emphasized, along with quick changes in grip for multiple attacks/parries.
The Jitte is the single-pointed Japanese equivalent of the Okinawan sai and was primarily used by Japanese police during the Edo Period. It is a signature weapon in several Japanese schools of jūjutsu and koryū.