The life of a ninja was one of training and discipline. They were trained to use an assortment of weapons to their full capacity. Some of these weapons allowed for stealth. A popular stealth weapon used by a ninja was the shuriken, or the ninja star. Many people wrongly think this weapon was meant to stick into an opponent. The shuriken was actually meant to slice into the skin, often delivering poison to the blood stream. There are two main types of shuriken, the Hira shuriken and the Bo shuriken, also known as the plate type and the stick type. These two main types make up the 40 or 50 known types. Charcoal was caked on the surface of these weapons to make them less noticeable.

The Bo shuriken isn't what you typically think of when you think of a ninja star. They are like a steel spike that in 5 to 8 inches long, and ranges in weight from 1.2 to 5.4 ounces. They're usually four-sided, but can be round or octagonal. They are confused with the kunai, which is a similar shaped item but is used for stabbing but is sometimes thrown. Often the Bo shuriken was made from every day items and would derive it's name from the item it was made such as kugi-gata (nail form), hari-gata (needle form) and tantō-gata (knife form). There were also those named for items they resembled such as hoko-gata (spear form), matsuba-gata (pine-needle form). Still others have names that simply describe their functions such as kankyuto (piercing tool form), kunai-gata (utility tool form), or teppan (plate metal) and biao (pin). There are many instances of this type of implement being used throughout Japanese history. This weapon was thrown in many ways, but all require the blade leaving the hand through the fingers in a smooth, controlled flight.

The Hira shuriken, also known as shaken, is what people commonly think of when they think of the ninja throwing star. These shuriken were made from thin, flat pieces of metal that came from a variety of sources including hishi-gane (coins), kugi-nuki (carpentry tools), spools and senban (nail removers). These shuriken generally have a hole in the center of the small blades which are sharpened on the ends. The holes allowed for easy transport as the shuriken could be strung on a belt. The holes also provided aerodynamic and weighting effects when the item was thrown. The shapes of Hira shuriken could be used to identify which ryu or school it was associated with as different school prefered different shapes. Now the ninja star is ually identified by how many points it has.

There are two other type of shuriken that had names, the Testsumari and Higuruma-Ken. The Testsumari was a bally type shuriken, and the Higuruma-Ken had gun powder set in the center and had a fuse. Both were too bulky to be portable while maintaining stealth. In old Japan learning to throw the ninja star was a master course for ninja to study called Shuriken-jutsu. It is a skill that can still be studied today.