Shuriken is the common name for Japanese concealed weapons designed for throwing. The word shuriken, consisting of the signs "Shu", "Ri" and "Ken", literally translates as "blade hidden in the hand".
There are two main types of shurikens, which are: bo shuriken - long, thin cylindrical rods of various shapes and thicknesses, and shaken - made of flat metal discs.
Undoubtedly, the shuriken is best known as a weapon used by the ninja. Unlike the samurai, throwing weapons were a major arsenal for the ninja, perhaps because the ability to kill the enemy at a distance was entirely in their best interests.
Some of the types of shuriken they wore were:
Wedge-shaped, which they hid in their sleeves and in the saya (Ninja's scabbard) and often smeared with poison or paralyzing substances.
Star-shaped, pyramidal and rectangular, which were often thrown into the ground while escaping to slow down the enemy.
Usually masked killers wore 9 shurikens because they thought that number brought them luck. Smoke or gunpowder firecrackers were often attached to large terra shurikens, using them to cause panic when attacking.