Ashiko
The Ashiko were spiked claws that were worn on the feet. This helped the Ninja climb faster and more efficiently on their missions. As well as a great climbing aid, it could also be used in combat to deliver deadly kicks.

Bokken
A bokken is a wooden sword usually used for sword training. When a student begins to work with a sword, he learns basic maneuvers with a bokken. However, the bokken can also be used as an effective weapon since it is made of strong, heavy wood. In fact, many Ninja preferred to use the bokken on a mission than a regular sword.
The reasons for this are that a bokken is lighter and easier to carry, there is no risk of cutting oneself, bokken are very easy to camouflage since they can be stained or painted, and, when using proper techniques, a bokken can easily break bones and damage internal organs.

Bo/ staff
The staff was one of the most important weapons in the ninja's arsenal. It was generally around 6 feet in length, made of hard wood or bamboo and was hollow. The reason for the hollow part was another trick of the ninja trade. By flicking the bow with great speed, the ninja could launch a poison tipped dart or small knife out of the open end of the staff, often catching the opponent off guard.
Another trick they had for the bo was to conceal a chain inside it. Then, when engaged in battle, it could quickly be released and used as a weapon. This was called a shinobi zue, and was easily disguised as a walking stick or staff.

Bows
The bow and arrow was a weapon used by the ninja as well as the samurai. There were two types of bows used, the short bow and the long bow. The arrows were sometimes dipped in poison to make them deadlier.

Chigiriki
This weapon is a 2 foot long straight stick, with a 2-1/2 chain attached to the top with a ball with spikes. This weapon is considered to be the japanese morning star. The chain could be fitted in side the stick like the Kusari-Gama/Kama, and used as a mace.

Darts
The ninja would use the poison darts differently depending on the situation. It was not uncommon for the ninja to carry poison darts in his mouth so they could be blown into the enemy's face at close range. If they needed to kill someone quietly, a dart could easily enter the body and be withdrawn without leaving a mark. From a distance the dart could be shot with a blowgun.

Fukiya/ blowgun
The fukiya, or blowgun, was a staple in the Ninja's arsenal since it was so versatile.
The fukiya was used to shoot darts (sometimes poisoned) at an enemy from a distance and, since it made almost no noise, the Ninja's hiding place wasn't threatened by using this weapon. Aside from launching darts, the blowgun could be used as a snorkel while the Ninja was underwater. Since the fukiya was made of bamboo, it blended in with the reeds in the water, therefore enabling the Ninja to stay submerged for hours, if necessary.
Metsubishi could also be delivered through the fukiya by shooting small paper containers filled with pepper and metal shavings at an enemy's face.

Hanbo
A bo 3 feet in length can be concealed as a cane. Can be used like a bokken. May also conceal things inside, like a sword blade or a chain.

Hoko
This weapon looks like a sai mounted on top of a jo. The Hoko was mostly made out of bamboo and was a very good offensive, as well as a very good defensive weapon. It was used in a stabbing motion, there are some variants of this weapon.

Jo
The jo was just like the bo, it was just shorter. It was 4 feet long and was a very effective offensive and defensive weapon. Excellent for blocking and easily used as a club or knife.

Kakute
The Kakute were rings that the kunoichi wore that were dipped in poison. The rings could be made out of metals, and tempered wood. The ninja would quietly strangle enemies with the ring stuck in their neck. It was far less messy then using a sword, and left very little evidence on how the victim died.

Kama
Kama are the basis of the kusari-gama. Kama is just the sickle on it's own. They are usually used in pairs and swung in various arcs, crescents etc.
All sorts of slashing motions combined with the forward momentum of the ninja they can cause some devastating damage. The blade of the Kama is roughly around 11-12 inches. The handle is slightly longer. Original sickles had a longer blade and shorter handle.

Kusari Gama
The Kusari-gama is a combination of a sickle (short scythe) and a long chain with a weight attached to the end of it. The sickle was used in a slashing or stabbing motion, as well as used to block and hook opponents weapons. By holding the chain portion of the weapon, the sickle could be swung around to get a greater reach with it.
The chain portion of the weapon was most often used for trapping an enemy or his weapon. Once tangled up with the chain, the ninja could finish him off with the sickle. This was a weapon the ninja invented out of farming tools they used.

Koketsu Shogei
The Kyoketsu-shogei was a knife attached to one end of a long cord made of women's or horse hair, or sometimes chain. On the other end of the cord was a ring. The knife could be used in close quarters or swung around by holding on to the ring.

The Kunai was a small dagger-type tool that served primarily as a utility knife. It's secondary use was as a weapon, with a sharp point and short handle it was a great throwing weapon. It was also a great close combat weapon as it could be used in very tight situations.
Some other uses for the kunai include a climing device, a hammering tool, a make-shift spear tip just to name a few.

Manriki Gusari
The Manriki Gusari was a chain usually about 3 feet long, and weighted at both ends. It was developed as a self-defence weapon but was also a wicked offensive weapon in the hands of a ninja. It was small and easily concealed in the palm of the ninja's hand, or in a sash.
While holding one end of the chain, it could be swung around and used as a whip. The weighted end could cause a great deal of damage.

Neko-te
The Neko-te were usually used by the kunoichi (female ninja). The weapon is strong iron fingernails that were fastened into leather bands fitted on the fingers, and resembled claws (not like that of of the shuko, ashiko) and were also dipped in poisons. The eyes were a favorite spot for slashing.

Nanchakus
Though not a primary weapon of the Ninja, nunchakus (also known as "nunchucks") were used because they could be adapted for many situations. Aside from being easy to carry, the nunchakus were used to defend against most any weapon from a bo to a sword. By trapping the blade of a sword with the chain between the two sticks, a Ninja could entangle and disarm a sword-weilding attacker.
The same concept applies to almost every other weapon. The nunchakus were not just used for defense, they could also be effectively employed against an enemy in an offensive way. The Ninja could strangle an opponent or even execute joint locks with the chain or cord between the two sticks.

Naginata
The Naginata is like a bo but it has a blade at the end.

Ono
The Ono, or battle axe, was a very powerful weapon used to smash through castle gates, knock opponents off their horses or totally destroy anyone attempting to fight with a lesser weapon. The Ono was generally 4 feet long with a heavy, oversized steel blade. The weight of this weapon demanded great skill from the user in battle.

Shobo
Shobo was a small weapon that was used for striking pressure points within the body, the neck was the best place to strike. It was a ring fitted on the middle finger and a piece of sharp/dull wood attached, there are many variants of this weapon.

Shuriken
The Shuriken is the trade mark ninja weapon made famous by the movies and stories about the ninja. The Shuriken was simply a flat piece of metal with sharpened points that were thrown at the enemy.
The Shuriken was not originally designed as a killing weapon. It was mostly used to distract or deter so the ninja could escape. While in the midst of a get-away, the Shuriken could be thrown at the samurai chasing the ninja, possibly making the samurai think twice about continuing the chase.
Although the Shuriken was not intended to kill, it was easily made lethal by dipping the edges in poison. This was effective, but sometimes it backfired when the ninja would accidentally cut himself while digging around for it, thus poisoning himself.
Shuriken were also designed to hit the opponent then bounce away out of sight. This way a ninja could fool an unsuspecting guard or sentry into believing he had been cut by an invisible swordsmen. (One of many mental tricks)

Tanto
The tanto, or knife, was an important weapon in the ninja's arsenal. Like the ninja-to, the tanto was not made of the high quality steel that the samurai's sword was but the ninja made up for this by using the tanto as a multi-purpose tool.
The tanto was used to pry open doors, dig holes or small ditches, or it could be thrown like a shuriken. Of course, the tanto was also used to cut and stab an opponent.

Tessen
The Tessen was a folding fan with an iron frame and, when folded, was used to club an enemy. A few different variations were invented, including one with a sharp edge on the outside of the framework so that, instead of only being able to club a person, the ninja could cut as well.

Swords
The ninja sword (ninja-to) was different than that of the samurai. The long sword that the samurai carried was made of high-carbon steel, and took months to have made. They were hand made specially for each samurai, taking great care to make a very high quality sword. It was so sharp that it could easily cut a man in two, even through their armor. The length of the samurai swords averaged around 26 1/2 to 37 inches.
The ninja sword was considerably shorter, only 24 inches, and the quality of the swords was much poorer. The reason for the poorer quality was the way they used the sword as opposed to the way the samurai used theirs. Samurai would swing their sword, severing limbs and slashing at the opponent. Ninja, on the other hand, used the sword more in a stabbing motion. To use the blade of the ninja sword effectively you would have to use a sawing motion when the blade came in contact with the opponents flesh.
Another reason for the poor quality of the swords is that since ninja were mostly mountain people and outlaws, they could not afford to hire expert sword smiths like the samurai could. Also their own sword smiths did not have access to the right resources to be able to make curved edge swords with well constructed blades. If a Ninja could overcome a samurai he would take his swords, simply because they are better.
Although the ninja sword was smaller and poorer quality, it still had its advantages. The scabbard for instance was made longer than the sword, about 3 to 4 inches longer. At the end of the scabbard there was a hidden compartment that was used to hide small weapons such as spikes, daggers or small amounts of poisons. Another use the sword had was that it could act as a small step by jamming the blade into the ground, the ninja could use the hand-guard as a step to get that extra height needed to scale a wall. Because the blade was not very sharp, the ninja could also use it as a hammer by holding onto the blade (carefully) and hitting with the handle. Also it was common to have the tip of the scabbard come off so it could be used as a snorkel. Another reason for using the Ninja sword was so that the ninja would be ale to weild it within small corridors on various missions.

Tetsu-bishi
Tetsu-bishi (also known as calthrops) are small metal weapons shaped so that one point is always up. They, like the shuriken, were a weapon used for distraction while fleeing. The ninja would scatter the calthrops behind them and anyone unlucky enough to step on them would not likely continue with the pursuit. They could also be thrown, and dipped in poison like the shuriken.

Yari
The Yari was typically 5 feet long with a 6 inch blade and the handle often contained a hidden chain or knife.