Shuriken

A shuriken (Japanese 手裏剣; literally: "sword hidden in user's hand") is a traditional Japanese concealed weapon that was generally used for throwing, and sometimes stabbing or slashing. They are sharpened hand-held blades made from a variety of everyday items, such as needles, nails and knives, as well as coins, washers, and other flat plates of metal. Shuriken is the name given to any small-bladed object, while shaken is traditionally used to indicate the well-known "throwing star".

Shuriken are commonly known in the West as throwing stars or ninja stars although they were originally designed in many different shapes. The major varieties of shuriken are the bō shuriken (棒手裏剣, stick shuriken) and the hira shuriken (平手裏剣, flat shuriken) or shaken (車剣, also read as kurumaken, wheel shuriken).

Shuriken were supplementary weapons to the sword or in a samurai's arsenal, although they often had an important tactical effect in battle. The art of wielding the shuriken is known as shurikenjutsu and was taught as a minor part of the martial arts curriculum of many famous schools, such as Yagyū Shinkage-ryū, Tenshin Shōden Katori Shintō-ryū, Ittō-ryū, Kukishin-ryū, and Togakure-ryū.

Bo-shuriken are throwing weapons consisting of a straight iron or steel spike, usually four-sided but sometimes round or octagonal in section. Some examples have points on both ends. The length ranges from 12 to 21 cm (5–8 ¹⁄₂ in) and the average weight from 35 to 150 grams (1.2–5.4 ounces). They should not confused with the kunai, which is a thrusting and stabbing implement that is sometimes thrown.

Bo-shuriken were constructed from a wide variety of everyday items, hence there were many shapes and sizes. Some derived their names from the materials of which they were made, such as kugi-gata (nail form), hari-gata (needle form) and tantō-gata (knife form); some were named after an object of similar appearance, such as hoko-gata (spear form), matsuba-gata (pine-needle form); others have names that are a simple description of the object being thrown, such as kankyuto (piercing tool form), kunai-gata (utility tool form), or teppan (plate metal) and biao (pin).

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