Shuriken A shuriken ( Japanese 手裏剣 ; literally : " sword hidden in the hand " ) is a traditional Japan ese 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 though they took many different shapes and designs during the time they were used . 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 mainly a supplemental weapon to the more - commonly - used sword or other in a samurai warrior ' s arsenal , though they often played a pivotal tactical role in battle . The art of wielding the shuriken is known as shurikenjutsu and was mainly 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 . Bo - shuriken are throwing weapons consisting of a straight iron or steel spike , usually four - sided but sometimes round or octagonal in shape . They are usually single - pointed , but some have points on both sides . The length of bo - shuriken ranges from 12 to 21 cm ( 5 – 8 in ) and the average weight was from 35 to 150 gram s ( 1 . 2 – 5 . 4 ounces ) . The " bo - shuriken " is thrown in a number of ways , such as overhead , underarm , sideways and rearwards , but in each case , the throw involved the blade sliding out of the hand through the fingers in a smooth , controlled flight . This is not to be confused with the kunai , which is a thrusting and stabbing implement that is sometimes thrown . The major forms of throw are the " jiki da - ho " ( direct hit method ) , and the " han - ten da - ho " ( turning hit method ) . These two forms are technically different , in that the former does not allow the blade to spin before it hits the target , while the latter requires that the blade spin before it hits the target . " Bo - shuriken " were constructed from a wide variety of everyday items , and thus there are many shapes and sizes . Some derive their name from the materials they were fashioned from , such as " kugi - gata " ( nail form ) , " hari - gata " ( needle form ) and " tantō - gata " ( knife form ) ; others are named after the object to which they appear similar , such as " hoko - gata " ( spear form ) , " matsuba - gata " ( pine - needle form ) while others were simply named after the object that was thrown , such as " kankyuto " ( piercing tool form ) , " kunai - gata " ( utility tool form ) , or " teppan " ( plate metal ) and " biao " ( pin ) . Other items were also thrown as in the fashion of bo - shuriken , such as " kogai " ( ornamental hairpin ) , " kogata " ( utility knife ) and " hashi " ( chopsticks ) , although these items were not associated with any particular school of shurikenjutsu , rather they were more likely just thrown at opportune moments by a skilled practitioner who was skilled in a particular method or school . The origins of the bo - shuriken in Japan are still unclear despite continuing research in this area . This is partly because shurikenjutsu is a secretive art , and also to the fact that throughout early Japanese history there were actually many independent innovators of the skill of throwing long , thin objects . The earliest known mention of a school teaching shurikenjutsu is Ganritsu Ryu , prevalent during the 17th century . This school utilized a long , thin implement with a bulbous head , thought to be derived from the arrow . Existing examples of blades used by this school appear to exhibit a mixture of an arrow ' s shape with that of a needle traditionally used in Japanese leatherwork and armor manufacture . There are also earlier mentions in written records , such as the " Osaka Gunki " ( 大阪軍記 , the military records of Osaka ) , of the standard knife and short sword being thrown in battle , and Miyamoto Musashi is said to have won a duel by throwing his short sword at his opponent , killing him . Hira shuriken / shaken . Hira - shuriken are constructed from thin , flat plates of metal derived from a variety of sources including " hishi - gane " ( coins ) , " kugi - nuki " ( carpentry tools ) , spools , and " senban " ( nail removers ) , and generally resemble popular conceptions of shuriken . They often have a hole in the center and possess a fairly thin blade sharpened only at the tip . The holes derive from their source in items that had holes – old coins , washers , and nail - removing tools . This proved convenient for the shuriken user as well , as the weapons could be strung on a string or dowel in the belt for transport , and the hole also had aerodynamic and weighting effects that aided the flight of the blade after it was thrown . There is a wide variety of forms of hira - shuriken , and they are now usually identified by the number of points the blades possess . As with bo - shuriken , the various shapes of hira - shuriken were usually representative of a particular school ( ryū ) or region that preferred the use of such shapes , and it is therefore possible to identify the school by the type of blade used . Usage . Contrary to popular belief , shuriken were not primarily intended as a killing weapon , but rather as a secondary weapon that sometimes played a role supportive to a main weapon , usually the sword or spear . Shuriken were primarily used to cause either nuisance or distraction . Targets were primarily the eyes , face , hands , or feet — the areas most exposed under armor . The shuriken would sometimes be thrown in a way that cuts the opponent and becomes lost , later causing the opponent to believe that they were cut by an invisible swordsman . Shuriken , especially hira - shuriken , were also used in other novel ways — they might be embedded in the ground , injuring those who stepped on them ( similar to a caltrop or makibishi ) , wrapped in fuse to be lit and thrown to cause fire , or wrapped in a cloth soaked in poison and lit to cover an area with a cloud of poisonous smoke . They can also be used as a handheld striking weapon in close combat . There are reports of shuriken being coated with poison , intended either for a throwing target or for whoever may pick them up when left in a conspicuous place . Other reports indicate that shuriken may have been buried in dirt or animal feces and allowed to harbor the bacterium " Clostridium tetani " — if the point penetrated a victim deeply enough , the bacteria transferred into the wound could cause a then - incurable tetanus infection . Shuriken are a simple weapon , but their historical value , thanks to their wide variety of uses and the ready availability of material from which they could be made , has increased . Unlike the treasured katana and other bladed weapons , antique shuriken are not often well preserved , largely due to their original status as expendable weapons . Today . Modern shuriken , unlike historical ones , are most often made of stainless steel and are commercially available in many knife shops in Europe and North America or online . They are however illegal to possess or carry in some countries ( " e . g . " , Canada , Germany , United Kingdom ( manufacture , sale , distribution and import ) ) while in some countries , such as the United States , some regions prohibit them ( " e . g . , " California , Indiana , New York ) , while others allow them . In some cases they may also be allowed but still subject to specific local legislation . Owners may be required to possess a certificate for the possession of knives .