Fukuro shinai (bamboo sword covered with a sleeve) (袋竹刀)
Fukuro shinai (written as 袋竹刀) is a tool used in martial arts that had been used in swordsmanship training before the bamboo sword was devised. Fukuro shinai is also written as 袋韜 or 袋撓. In the Shinkage-ryu school of swordsmanship, it is believed that Nobutsuna KAMIIZUMI devised the fukuro shinai, which is also known as "hikihada-shinai bamboo sword." Even now, fukuro shinai are used in training in many schools of swordsmanship, such as the Shinkage-ryu school, Kashima-Shintoryu school, Maniwanen-ryu school, Onohaitto-ryu school and the Jigen-ryu school.
The Shinkage-ryu school uses a unique fukuro shinai with a red lacquer-coated surface, without a tsuba (sword guard), the only school to do so. Other schools frequently use a fukuro shinai equipped with a tsuba made from cowhide, koyori (string made from twisted paper), or other materials.
The Jikishinkage-ryu school of swordsmanship also uses a martial arts tool called a 'fukuro shinai' (袋韜), however, its appearance differs from that of ordinary fukuro shinai. It is made from a standard bamboo sword with the tsuba removed, and only half of its length is covered with a leather sleeve.
Many schools use bamboo as a material to make the fukuro shinai by dividing one end into four parts lengthways up to halfway. They then divide the middle third of the divided part vertically into eight parts and the end third into sixteen parts in total, applying a thick cowhide and sewing it into a cylinder shape in order to protect the bamboo sword. However, some schools divide the bamboo into a different number of parts. The length of the fukuro shinai also differs among schools. For example, the Shinkage-ryu school fixes the length at about 100 cm, or for kodachi (small sword) at about 53 cm, coating the leather sleeve that covers the sword with red lacquer to protect the surface from wear and tear; the seam of the sleeve is used to represent the sword's blade. Fukuro shinai are quite light, weighing a little more than a vinyl umbrella.
The leather sleeve covering the sword originates from a tool used by samurai when they traveled a long distance, used to protect the sheath from dirt and damage by placing the tool along the whole length of the sheath; the wrinkle on the surface of the tool resembles the skin of a toad, and as such it is called hikihada (skin of toad).
Unlike in training using regular wooden swords which have the potential to cause serious injury and even fatal accidents even if trainees strike at their opponents for practice, in training using fukuro shinai, trainees can strike at their opponents with all their might (even so, some trainees may be injured, and trainees often suffer from considerable pain when they are struck).
One anecdote tells of Kagekane HIKITA, a pupil of Nobutsuna KAMIIZUMI and also his nephew, having a string of consecutive victories using a fukuro shinai against opponents who used a wooden sword. It is said that he sometimes made opponents faint.
The Yagyu Shinkage-ryu school, while using a wooden sword for some types of kata (basic form and movement), has passed down to the present forms of kata training using fukuro shinai. Moreover, the Maniwanen-ryu school even now gives training with fukuro shinai used together with a unique form of protective tool, to pupils who have already mastered the kata (form) training using a wooden sword.
Care and others
There is no specific way to take care of fukuro shinai. After repeated use of fukuro shinai the lacquer covering the leather sleeve often becomes spotted. Also, being hit repeatedly, the sword gradually becomes warped in the opposite direction from its original curvature. Provided the lacquer is repainted fukuro shinai can be used for a long time. Even though the number of companies manufacturing fukuro shinai is decreasing, veteran trainees can make them themselves referring to instructions passed down orally.