Sai (weapon)

The sai (釵) is a traditional Okinawan weapon. The basic form of the weapon is that of a pointed, dagger-shaped truncheon, with two curved prongs called yoku projecting from the handle. The ball of the handle is called the knuckle. Multiple sai are called zai.

There are many other variations on the sai with varying prongs for trapping and blocking. The monouchi or shaft of traditional sai are round, while some reproductions have adapted an octagonal central shaft. The yoku are usually symmetrical but the manji design developed by Taira Shinken employs oppositely-facing yoku in an approximation to the manji (the Japanese term for the Buddhist symbol, the swastika) from which it takes its name.

Technique
The sai is typically used in pairs, with one in each hand. Five kata are commonly taught, including two kihon kata. The style includes a variety of blocks, parries, strikes, and captures against attackers from all directions and height levels. Use of the point, knuckle and central bar is emphasized, as well as rapid grip changes for multiple strikes and blocks.

The sai's utility as a weapon is reflected in its distinctive shape. It is primarily used as a striking weapon for short jabs into the solar plexus but it also has many defensive techniques. With skill, the prongs could be used to rap or even fracture a katana's blade.

There are several different ways of wielding the sai, which give it the versatility to be used both lethally and non-lethally. One way to hold it is by gripping the handle with all of the fingers and pinching the thumb against the joint between the handle bar and the shaft. This allows one to manipulate the sai so that it can be pressed against the forearm and also help avoid getting the thumb caught in the handle when blocking an attack. The change is made by putting pressure on the thumbs and rotating the sai around until it is facing backwards and the index finger is aligned with the handle.

The knuckle end is good for concentrating the force of a punch, while the long shaft can be wielded to thrust at enemies, to serve as a protection for a blow to the forearm, or to stab as one would use a common dagger. In practice, some prefer to keep the index finger extended in alignment with the center shaft regardless of whether the knuckle end or the middle prong is exposed. The finger may be straight or slightly curled. Used in this way, the other fingers are kept on the main shaft, with the thumb supporting the handle.

The grips described above leverage the versatility of this implement as both an offensive and a defensive weapon. Both grips facilitate flipping between the point and the knuckle being exposed while the sai is held in strong grip positions.

In popular culture
The sai are often portrayed as much more offensive weapons, being used as swords, daggers, and throwing knives. Little play is given to striking with the knuckle. Thus, the traditionally blunt and rounded weapon is often portrayed as a blade. Western popular culture often portrays the sai as a weapon of the ninja, but it was never actually used in any traditional martial arts from mainland Japan.

Notable examples of the sai in popular culture include:
 * Teenage Mutant Ninja Turtles: The character Raphael uses twin sai.
 * Conan the Adventurer: An episode of the series is named "Sword, Sai & Shuriken".
 * Marvel Universe: Sai are the signature weapons of Elektra, and are wielded by Jennifer Garner in the films Daredevil and its spin-off Elektra.
 * Mortal Kombat: Female ninja Mileena uses double sai as her primary weapons. The characters Khameleon, Li Mei and Sareena have also used sai.
 * Street Fighter: The Storytelling Game: One of the examplary Condenders in the game is the character named Sai (aka The Green Ninja), who chose as weapon "the sai, which disarms quickly without killing".
 * Super Sentai: In the series Kyōryū Sentai Zyuranger and Mighty Morphin Power Rangers, Dan the Tricearanger, Billy Cranston (the Blue Ranger), Boi the Tigerranger and Trini Kwan (the Yellow Ranger) all wield weapons resembling sai, as does a villainess named Camille/Mele..
 * The Mummy Returns: Princess Nefertiri and Anck-Su-Namun each use a pair of golden sai.
 * Xena: Warrior Princess: Gabrielle uses a pair of sai as her primary weapons in seasons 5 and 6. A former pacifist, she makes note of the versatility of the sai by mentioning their lethal and non-lethal uses; to demonstrate this, she often uses the knuckle to strike her opponents in battle and rarely uses the shaft to make a killing blow.
 * Matrix Reloaded: Neo uses a pair of sai when defending himself against the henchmen of The Merovingian during the Chateau scene where he shows the tremendous versatility of the weapon by parrying and blocking numerous attacks.
 * Bleach: Sun-Sun, A minor character from the manga Bleach uses a sai as her zanpakuto.
 * Napoleon Dynamite: Napoleon picks up a pair of sai in the thrift store.
 * Ronin Warriors: The character Lady Kayura uses twin sai.