Kendama: Japan’s Traditional Ball and Cup Toy

A kendama (けん玉) is a Japanese toy consisting of a hammer-shaped handle connected by a string to a ball. Made of wood, the ends of the base and the crosspiece of the hammer are cupped so that they can catch the ball, and the ball has a hole in it that can fit on a spike on the end of the hammer.

To play with a kendama, the ball is jerked or swung and caught in one of the cups or impaled on the spike. More advanced tricks involve sequential catches, juggles, and balances often not even involving the cups or spike.

Kendama History

There were kendama-like toys that predate the Japanese version. In particular a version called a bilboquet (or bilbouquet), which was missing the crossbar piece, was known in 16th century France, where King Henry II was said to have played it. A version of the bilboquet called the balero is still popular in Mexico.

Although the Ainu in Japan are thought to have developed a bilbouquet style toy, the kendama probably traces back to the introduction of the bilboquet from Europe at the end of the 18th century. In the early 20th century the Japanese kendama had acquired the two additional side cups and was called a nichigatsu ball (日月ボール). In 1919 Hamaji Egusa of Hiroshima successfully registered a sort of early Japanese style patent for the device. At this point the basic form of the kendama was essentially fixed.

The Kendama in Contemporary Japan

The kendama has a split personality in Japan. On the one hand inexpensive kendama toys of varying designs are common and most families have one laying around somewhere. Most Japanese children have a bit of experience in playing with them, but are not particularly skilled. Game machines or other more modern entertainment now hold the attention of Japanese children.

But a more serious form of kendama play is overseen by the small staff of the Japan Kendama Association (日本けん玉協会), founded by author and kendama enthusiast Issei Fujiwara in 1975 and reorganized as a nonprofit association in 2002. Headquartered in cramped offices a few blocks from the grounds of the Imperial Palace in Tokyo, the JKA sets the technical specifications for licensed competitive kendamas, establishes rules and regulations, organizes competitions (mostly for children), awards kyu and dan level rankings to kendama “athletes,” much as in the martial arts world, and works with the Ministry of Education, Culture, Sports, Science and Technology in preserving the kendama as a piece of Japanese traditional culture.

The JKA supports itself with license fees from a small number of kendama makers who make competitive kendamas with the JKA seal, corporate sponsorships, and annual dues collected from members who wish to compete and receive an official level ranking.

Anatomy of the Modern Japanese Kendama

Kendamas approved by the JKA are composed of five parts:

  • The ball (玉 tama)
  • The ken (or stick, ken means “sword,” けん ken)
  • The crosspiece (or cup body, 皿胴 sarado)
  • The string (usually thin nylon, 糸 ito)
  • The bead (a plastic washer that holds the ball on the string, 太めのビーズ futome no biizu)

The tip of the ken is called the spike or point (けん先 kensaki). The ridge around the handle of the ken is called the slip stop (すべり止め suberidome). The base of the ken is the center cup (中皿 chuuzara). Between the center cup and the slip stop is the JKA seal, indicating authorization and certification by the JKA as a competitive kendama (日本けん玉協会公認シール Nihon Kendama Kyokai kounin shiiru). For each model of kendama the JKA selects a distintive colors in which to print the center portion of its seal.

The crosspiece has a small cup (小皿 kozara) and a big cup (大皿 oozara). On each side of the crosspiece is a small beveled hole for the string to pass through. The hole through which the ken passes is tapered to fit the conical shape of the ken.

Each cup has a reinforcing edge called the cup edge (ふち fuchi), to thicken the cup rim and prevent it from easily breaking when hit by the ball.

A hole large enough to accommodate the spike is drilled most of the way through the ball. At the entrance it is beveled to about 2 centimters in diameter to make it easier to spike the ball during tricks, and at the far end a small hole is drilled through to the other side for the string to fit through The string passes through a plastic bead and is knotted to hold it onto the ball. The other end of the string passes through one of the holes in the crosspiece and a knot (糸のむすびめ ito no musubime) is tied. There is no bead used at this end because it is usually pulled out and fixed by the friction of the ken penetrating the crosspiece. Another option is to further pass the string through a hole drilled through the spike, although this is hard to do without a special needle or thin bodkin.

The ken and the crosspiece on JKA kendamas are not glued together, to allow for disassembly to replace the string or convert the kendama to right- or lefthand use. Likewise, the strings are not glued or nailed into the kendama, but are attached through a hole in the crosspiece and held in by friction and a knot. Consequently, JKA kendamas are not for use by young children, as they can fly apart during high centrifugal force tricks and break windows or teeth if not frequently checked for tightness.

Although the shape and dimensions of the JKA kendamas are fairly consistent across models, the weights of the kendamas and their pieces can vary considerably, depending on the woods used. Balls, which are 6 centimeters in diameter, can be as light as 55 grams or heavier than 75 grams, and overall weight varies between 115 grams and 140 grams. In addition, the gloss and slipperiness of the ball varies by the type of paint and varnish, and there are at least a couple of JKA kendama models where the ball is unpainted or only painted with a thin translucent whitewash.

The strings can be any length over 38 centimeters (35 for youth), but the longer the string, the more difficult it is to perform tricks, so most kendama athletes use strings from 39 to 42 centimeters.

Note that the ken on JKA kendamas is a single piece that penetrates through the crosspiece. Many toy kendamas are constructed from a separate handle piece and spike piece, both glued into the crosspiece.

Ironically, many non-JKA toy kendamas are actually more difficult to perform tricks on than the JKA competition kendamas. The hole in the ball may not be beveled; the hole may not be drilled as far into the ball making it more lopsided and hard to spin accurately; the strings may be longer or stretchier; and the small and center cups are often smaller relative to the ball than on the JKA kendamas. Because of that, many kendama athletes own non JKA kendama to practice on in the same way that many competitive swimmers will use baggy beach swim trunks on occasion during training to give them more resistance and make swimming more difficult.

JKA Kendama Licensees

Japanese Kendama Patent 2002-346011 The JKA holds a number of Japanese patents on the shape and construction of its approved, official kendamas. The JKA occasionally makes insignificant changes in its specifications, presumably to stay one step ahead of expiring patents. The only currently valid patent on the competition kendama is a patent on the idea of offsetting the string hole slightly to the left of center (or right of center on the left-hand string hole) for the purpose of imparting somewhat better balance when holding the kendama. However, no current kendamas seems to to incorporate this feature. The current kendama model is called the JKA16-2, replacing the earlier JKA16.

In order to make competitive kendamas of this precise shape and style manufacturers in Japan must negotiate and obtain a license from the JKA, which entitles them to place the JKA seal on the base of the ken. Makers are not allowed to sell JKA-shaped kendamas without a license and without the seal.

Currently the JKA licenses the following two makers to produce authorized competitive kendamas:

  • Yamagata Koubou (山形工房) produces the Oozora model (大空), introduced in 2008; Yamagata Koubou has been making competitive kendamas since 1975, and was the first JKA-licensed manufacturer; Yamagata Koubou holds a Japanese patent on an original 5-cup kendama design
  • H Alpha (エイチアルファ) produces the TK16 Master model

Two JKA kendamas were recently withdrawn from the market:

  • Art Yoshii (アートヨシイ) produced the Shin Sakura model (新さくら), but the company has since gone bankrupt
  • Kazuma Iwata

  • Iwata Mokko (イワタ木工) in Hiroshima, a maker of traditional Japanese calligraphy brushes distributed nationwide, produced the Mugen (夢元), known for their unusual ball colors, including a gold kendama; Iwata Mokko’s production is currently on hiatus due to disagreements with the Japan Kendama Association, but could conceivably ramp up again if the issues are resolved; a 2005 Japanese patent and a design patent held by the JKA prevents Iwata Mokko from making Mugens without a JKA license, and even the stickerless Mugen Kotobukis cannot be made without the JKA’s permission; Iwata Mokko has twice applied for a patent of its own for an original kendama design, but has been turned down both times; Kazuma Iwata, 20-something son of the owner of Iwata Mokko, made all the Mugens by himself, crafting the balls from cherry wood and the kens from beech, and was the subject of an award-winning NHK documentary in 2006


Various tricks require that the kendama be held in different ways. The major grips are as follows:

  • Sara grip: In the sara grip your fingertips grasp the ken under the sara-do with the thumb and index finger, and placing the middle finger and ring finger in either the big cup or small cup. the handle below the slip stop touches the webbing between your index finger and thumb. This grip is used for catching the ball in the big or small cups or in doing the moshikame (see below).
  • Ken grip: The ken grip the kendama is held point up with the thumb on one side of the ken and the remaining fingers gripping the other side. Some people stabilize the ken by placing their pinky on the same side as their thumb, just below the slip stop.
  • Ball grip (or tama grip): In the ball grip you grip the ball with your thumb and index finger, hole side up, with your remaining fingers cupping the ball below. Some people curl their pinky away from the ball. Some grip with their fingers as far around the ball as they can, and some grip with their fingers and thumb diametrically opposite each other. The thumb and forefinger can be above the “equator” of the ball and gripping tightly, or below the equator and gripping lightly. The latter adds more control and sensitivity for some tricks, but shouldn’t be used around glass windows, computer displays, and other breakable objects, as the ball sometimes flies away in the heat of excitment.
  • Rosoku grip: For the rosoku trick (see below), the ken is held by the point between thumb and fingers, cup end up.

There are other grip variations and even ways of holding the kendama by the string, used in more exotic or advanced tricks.

Tricks for Kyu Level Ranking

In Japan kendama rankings similar to those awarded in the martial arts world are awarded. The lower level goes from 10- to 1-kyu, and the higher level goes from 10- to 1-dan. Each level requries the satisfactory completion of all the tricks (技 waza) designated for that level, and each kendama athlete must start at the bottom and be ranked level by level. Since ranking is only available for paid-up members of the JKA, this system is quite a cash cow for the organization (certifications and rankings of various sorts are a major business in Japan).

The tricks in order from lowest level to highest level for each kyu ranking are as follows. For each level you need to successfully perform the trick at least once in ten tries. In addition, you need to perform the trick for the level below the level attempted twice in ten tries, and the trick below that three times in ten tries. For levels 6 through 1, an additional trick, the moshikame (もしかめ) must also be performed.

10-kyu: Oozara (Big Cup, 大皿)

The lowest ranking level requires that you simply be able to jerk the ball vertically from a dead hang into the big cup once in 10 tries.

9-kyu: Kozara (Small Cup, 小皿)

Kozara is the same as oozara, but the ball needs to be caught in the small cup. This needs to be done once and oozara needs to be done twice, each in 10 tries, for a 9-kyu ranking.

8-kyu: Chuzara (Middle Cup, 中皿)

For 8-kyu the ball must be caught in the middle cup on the end of the ken. (Again, once in 10 tries, with the small cup done twice in 10 tries and the big cup three times.)

7-kyu: Rosoku (The Candle, ろうそく)

The candle trick is the same as the chuzara, except that the grip is different: You hold the ken by the point. This makes it a bit harder to catch and balance the ball.

6-kyu: Tomeken (Spike Catch, とめけん)

The spike catch (or pull up/in) involves jerking the ball up from a dead hang and catching the ball by inserting the ken spike into the ball’s hole. In addition to this trick (and performing the two lower tricks, as usual), to receive the 6-kyu rank and up you need to do the moshikame, which requires you to toss the ball between the big cup and the center cup, 4 cycles in one attempt for 6-kyu.

5-kyu: Hikoki (The Airplane, 飛行機)

The airplane requires you to grip the ball and jerk the ken up, flipping it and impaling the ball with the ken’s spike. This need not start from a dead hang. Ten moshikame cycles must also be completed.

4-kyu: Furiken (Swinging Spike Catch, ふりけん)

The furiken is similar to the tomeken of 6-kyu, but it’s made more difficult by swining the ball up, rather than starting from a dead hang. Twenty moshikame cycles are required.

3-kyu: Nihon Isshu (Trip around Japan, 日本一周)

The Trip around Japan starts with a small cup catch, then you toss the ball to the big cup, and finally you spike the ball. Thirty moshikame cycles are required.

2-kyu: Nihon Isshu (Trip around the World, 世界一周)

The Trip around Japan inserts a toss to the center cup after the large cup and before the spike. Forty moshikame cycles are required.

1-kyu: Toudai (The Lighthouse, 灯台)

The Lighthouse seems at first impossibly difficult, a trick more suited to the dan levels than the kyu levels: You grip the ball and jerk the ken from a dead hang and balance the ken right side up on the ball, center cup touching the ball, keeping it balanced and completely stationary on the ball for at least three seconds, without sliding it around and rebalancing.

Japanese children learn this in three steps: (1) First they learn to balance the ken on the ball by placing it directly on the ball and letting go. (2) Next they use their left hand (if they are right handed) and drop the ken from about a centimeter or two above the ball and try to catch it and balance it, moving the ball up to gently meet the falling ken. (3) Finally they repeatedly practice the full trick until they can do it. It’s one of those tricks that, if you put a certain amount of time into practicing it every day or two for two or three weeks, all of a sudden it comes to you and it seems simple.

If you’re having trouble with it, here are a couple more hints used by Japanese kendama masters in training, perhaps a little on the Zen side: (1) You have to psych yourself into believing you can do it. (2) When gripping the ball try to sense it as being weightless; then when the ken lands, feel only the weight of the ken. Need more? Jugglers suggest watching the spike of the ken rather than the contact point on the ball, although this is counterproductive for some people.

Moshikame (The Rabbit and Turtle, もしかめ)

Oh, yeah, we forgot to mention that fifty moshikame cycles are required, twice, in only two attempts, for 1-kyu (ikkyu).

Why is this trick called moshikame? The name “moshikame” comes from the first line of a Japanese children’s song called “Usagi to Kame” or The Rabbit and the Turtle, a song about the folktale of the tortoise and the hare (“Moshi moshi, kame-san, kame-san yo …“).

Japanese children sing this song while juggling the kendama ball between the big cup and the center cup, as a way to maintain the rhythm required for the trick. Here’s an example of a young girl on YouTube singing “Usagi to Kame” while doing the moshikame:

Here’s another example (from 1:05):

The lyrics in Japanese and a MIDI version of the melody can be found on this Japnaese song database Web site (Shift JIS encoding).

Tricks for Pre-Dan Level Ranking

Above the kyu level and below the dan level there is the pre-dan level. To be certified for this strange no-man’s land you need to perform several of the tricks necessary for the dan level.

In addition, you need to perform 100 cycles of moshikame, but if you have previously performed this in any certified JKA competition, you don’t need to perform it during pre-dan certification. 

Tricks for Dan Level Ranking

There are 6 dan levels, with the highest being 6 (unlike the kyu levels where the lower numbers are higher in rank). The dan levels require the following tricks:

Ken Isshu (Trip around the Prefecture, 県一周)

Ken-saki Suberi (The Point and Spike, けん先すべり)

Chikyu Mawashi (The Earth Spin, 地球回し)

Sakaotoshi (Spike the Lighthouse, さか落し)

Ura Furiken (Backside Swinging  Spike Catch, うらふりけん)

Uchu Isshu (Trip around the Universe, 宇宙一周)

Uguisu (The Nightengale, うぐいす)

Tsurushi Tomeken (The Coat Hook Spike Catch, つるしとめけん)

Unusual Kendamas

Outside of the realm of JKA kendama, toy kendamas and folkcraft kendamas, there have been many wacky kendamas made.

Iwata Mokko Big Kendamas

The classic wacky kendama is the mega kendama. Some of these things are too big to actually play, and are limited to appearances at kendama championships. But on the smaller end of the scale, Iwata Mokko, maker of the discontinued Mugen JKA kendama, has made scaled up but playable versions of the JKA kendama design (sans JKA sticker).

Iron Kendama

A Japanese student learning lathe techniques in shop class made this kendama out of iron rods. He did it as a learning experience over the course of a six-month class. He warns that this kendama cannot actually be used without serious risk of injury, as anyone who has almost broken a tooth or fractured a wrist learning the furiken with a wooden kendama can imagine.

Further Kendama Information

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