Why do different shapes of bokken exist?

Question

Bokken are supposed to mimic/represent a katana for training purpose. There are suburi bokken which are heavier than normal to train muscles and develop power. But why are there different shapes of 'normal' bokken? Is it just to be different or are there real differences between the swords that the bokken are supposed to represent between the different styles?

For example, see Nine Circles's specialise bokken section for example of different bokken by styles: jigen ryu daito, niten ichi ryu daito, etc...

Answer 1

Generally, there are a few points in which the sword will differ between arts. The history and mythology (or oral tradition) of the evolution of the Japanese sword (from ken or tsurugi to tachi to katana) spans thousands of years. Generally, differences may be caused by:

• Locality – The available material sources at the time may have led to a design out of practicality more than necessity. For instance, it's said that Miyamoto Musashi created a suburito from an oar that he found in order to prepare for a duel with Sasaki Kojirou.

• Temporality – The norms of the time shaped the crafting virtues of bokken. That is, if the swords of the time at which the ryu is founded are straighter (closer to tsurugi, as the differentiation was not immediate), then the bokken may mimic this.

• Proximity – The location relative to emerging schools of craftsmanship may result in choices of kisaki or relative weight.

• Necessity – Some ryuha have requirements of lighter, faster bokken to train movement, while others believe in using a heavier and thicker design to encourage powerful strikes. The contact of kukishin-ryu makes a thick tsuba a necessity.

Generally, the differences will be noted in terms of:

• Thickness – Bokken of Kashima Shin-ryu tend to be thicker than those of Yagyu Shinkage-ryu.

• Kisaki – The tip or point tends to differ amid styles. Common variations may be a blunt, chisel, or sword point.

• Length – Kukishin-ryu tends to favor a longer bokken, while Tenshin Shoden Katori Shinto-ryu is significantly shorter (by about half a foot). The length of the bokken used for Togakure-ryu is shorter still to emulate a style of sword developed for deception.

• Tsuba – The tsuba used on Kukishin-ryu bokken is a thick, wide piece reminiscent of a donut, while Tenshin Shoden Katori Shinto-ryu commonly uses none.

Generally, by researching into the histories of different schools, you can find the reasoning behind the choices they made. More often than not, someone at some point has explained it, and even the most secretive practices often end up as public knowledge.

Answer 2

To clarify a couple of points in other answers:

Weight: lighter bokken feel rather different to a katana. As already noted, you can do techniques with a kendo shinai that are not possible with a katana unless you are Conan the Barbarian! This is due to the light weight of the shinai vs a katana. A heavier bokken will be closer to the weight of a katana and thus there is less change when switching between them. So it depends on what your training goals are. In some cases, it is useful to practice with a lighter weight weapon to increase sensitivity. There are also very heavy wooden weapons to train strength and other aspects of the body (heading in the direction of kettle bell type training).

Resistance to contact: in some schools such as Kashima Shinryu, some of the kata use a bokken to strike a bokken. To avoid constant breaking of weapons, the bokken are thus both reasonably heavy and also straight - no curve. So it's horses for courses.

Answer 3

Bokken are both training tools and weapons in their own right.

The suburi bokken comes from the legend of Musashi. As the story goes, he was crossing a river on a boat to go to the duel of his life when he realized he didn't have his katana. He fashioned one of the oars into a sword. It was heavy, but Musashi was well renowned for his strength. He, of course, defeated his opponent.

The more traditional bokken was used as a training tool. It hurt when you were hit, but it didn't cut you. It was plain, without grooves, saya (scabard), or tsuba (hand guard). It was used primarily to learn the sword katas for beginners. Newer tools such as the iaito and the shinai replaced its use in more modern times. The iaito looks and feels more like a shinto (new blade/cutter) allowing the student to practice drawing the sword and notto (sheathing the sword). The shinai is used in modern kendo, as it produces fewer injuries.

Some schools still use the bokken, as it has a ha (edge) and mune (back). These features ensure that the waza (techniques) practiced translate better to a proper katana. Modern kendo includes waza that will only work with a shinai.

Outside of the suburi bokken which is studied as its own weapon, and builds strength (it's heavy), all the other variants of bokken are just modern conveniences to fit the tastes of the buyer. The hi (groove) only serves to lighten the weight of the bokken.

Answer 4

Swords come in different shapes and sizes. Bokken, to represent them as facsimile, should follow. This is sufficient explanation for variation in curvature, thickness, edging, grooves, or any other variables.

In addition, different styles demand different weights, shapes and styles for their bokken due to personal or organizational preferences that are often inscrutable. I would not be surprised if some of these preferences are only discussed internally in some cases.