Kobudo is an Okinawan term that refers to Kobujutsu or, ancient weapon art.
 
In 1477, during the Second Sho Dynasty, swords and other weapons were banned from Okinawa and the Ryukyu islands by Emperor Shoshin. All weapons on the island were collected and garrisoned in his royal castle in Shuri on Okinawa. It was as a direct result of Shoshin's edict that Okinawans turned to the development of open hand fighting. Although kobudo weapons are not really a part of karate, their development has shadowed the development and evolution of karate to the degree that they are almost inseparable.
In 1600 the Japanese invaded and occupied Okinawa. As a conquering army they used the continued prohibition of weapons as a method of controlling the population. This was combined with an attitude by the Japanese, that still permeates the island today, that Okinawans were second class citizens and not as good as Japanese. (Even today most any Okinawan will quickly inform you - "I am not Japanese, I am Okinawan!") Therefore only Japanese samurai's were permitted to own and carry weapons.
Okinawan karate further developed from it's Chinese roots. Just as the monks in China had developed weapons from seemingly innocent items such as the staff, so too did the Okinawans. These creative farmers and fishers resorted to weaponizing the implements of their everyday working life. They developed complex weapons forms for such items as the boat oar (eku), fish net floats (chesen kun bo), millstone handles (tonfa), top knot pints (jiwa) sickles (kama), saddle stirrups (tekkos) and the 6 foot staff (bo).
Over the years modern machinery and implements replaced most of the traditional kobudo implements, however they remained an integral part of kobujutsu.
With the growth and development of Shorin-Ryu Matsubayashi-Ryu karate certain kobudo weapons have remained closely aligned to us. These weapons include the Bo, the Sai, the Tuifa, the Kama and the Nunchakus. By adding weapons training to the traditional open-handed training, Grandmaster Nagamine felt the individual student could enhance their mental and physical training.

The Weapons of Kobudo Utilized in Shorin-Ryu, Matsubayashi-Ryu

bo

The Bo (boh) or 6 foot staff

The Bo is an early weapon of Okinawa. It differed in that it was utilized by peasants, monks and samurai alike. Fashioned of Okinawan hardwood, the Bo is 6 feet long and 1 1/2 to 2 inches in diameter. Many present day Bos taper at the ends. This is probably not the traditional style as the bo was utilized to carry water buckets and other items. If the original Bo was indeed tapered at the ends it would have been more difficult to keep items on it. Because of this original Bos are felt to have been non-tapered.
The Bo's size makes it a good weapon to use against swords and to disarm an opponent while allowing the Bo practitioner to remain at a safer distance. Manipulation of the weapon requires a thorough knowledge of basic karate stances and techniques
Shorin-Ryu utilizes the Bo for demonstrations, kata and practical self defense techniques. In day-to-day life many articles can be utilized as a Bo-like weapon; a broom or mop stick, a PVC pipe or even an umbrella. The Bo is also used to augment physical conditioning and balance.
tonfla
 
 

The Tuifa (twee-fa) or Tonfla (tone-fla) or grinder handles

Controversy surround the original use of the tuifa. It has been referred to as a rice grinder although some evidence exists to support it's use as a milestone handle. Either way it's use has also parrelled the development of karate.
The tuifa are very effective weapons for striking and blocking. The handle can be used to twirl the weapon thereby increasing it's reach. The sides of the weapon are used primarily for blocking and the ends for striking. Although generally used in pairs it is also an effective weapon when used singularly. Good evidence of this is seen with the adaptation of the Tuifa in a great number of police departments and correctional facilities around the world.
In Shorin-Ryu the tuifa is used in black belt weapons katas and in demonstrations.

nunchaku

The Nunchaku (noon-chuck-uu) or rice flails

The Nunchaku was originally a tool for thrashing rice, wheat or other grains. To the Japanese it appeared to be two harmless wooden sticks connected with a length of rope, braided horse hair or chain.
The Nunchaku were utilized to strike, block and trap an opponent. Stances utilized with the Nunchaku were the same as those utilized in karate so, again, the development of the two closely parelled each other. Use of the Nunchaku required the martial artist to be equally proficient with either hand. During it's use the weapons could be switched from one hand to the other as needed.
Most occidentals were introduced to the Nunchaku by Bruce Lee in the 1970s. Since that time the Nunchaku has been closely aligned to Okinawan and Japanese karate. It can be a "flashy" weapon and because of this it is frequently seen in Karate demonstrations. Many police departments carry Nunchakus.