Shuriken

[3][4][5][better source needed] The art of wielding the shuriken is known as shurikenjutsu[5] 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.

[8] The bo-shuriken is thrown in a number of ways, such as overhead, underarm, sideways and rearwards, but in each case the throw involves the blade sliding out of the hand through the fingers in a smooth, controlled flight.

This is partly because shurikenjutsu was a secret art and also due to the fact that throughout early Japanese history there were many independent exponents of the skill of throwing long, thin objects.

They 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).

This proved convenient for the shuriken user 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.

[12][7][better source needed] 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.

[6][7] Unlike the katana and other bladed weapons, antique shuriken are not often well preserved (although some are blackened in ash to prevent corrosion), largely due to their expendable nature.

However, in many countries and jurisdictions, they are illegal to possess or carry, such as in Belgium, the Netherlands, Canada,[14] Germany,[15] and the United Kingdom (manufacture, sale, distribution and import).