The Shell Game Kai Awase


‍   The origins of kai awase


Kai awase, (貝合わせ) the game of “matching shells” is included among a number of aristocratic pastimes belonging to the category mono awase (物合わせ), a “competition among things,” that was popular in the 11th and 12-century Japanese court. The subjects to be compared and judged ranged from man-made objects like poems, paintings, and musical instruments, to natural phenomena like flowers, roots of the calamus plant, birds, insects, and tray gardens. The examples of clamshells and of incense differ from the general format of mono awase pastimes, but share the basic element of competition, so I will lay out the general rules here. 

‍    A mono awase competition was divided into two teams, called the Left and the Right. The teams were usually composed of high-ranking related family members or affiliated persons. In the case of a poetry competition (uta awase歌合わ), arguably the most serious type of match, a lower-ranked person of exceptional poetic skills might be asked to join a team. (The fact that compositions could potentially end up in Imperial anthologies raised the stakes.) There were team colors—warm (purples and orange) for the Left, and cool (lavender-blue and yellow) for the Right. Young girls dressed in the team colors were drafted as assistants, and accompanying accoutrements were done up to match. Each side would present its object, whatever the category was, to the umpire, a courtier of high cultural recognition, who would decide which of the pair was superior. Judgments were recorded by each team’s official scorekeeper. 

‍    In modern Japan, a similar contest between performers on opposite sides is alive and well in the annual televised New Year’s Red vs. White Song Contest (Kōhaku Uta Gassen紅白歌合戦), which has been watched by the entire country since 1951. Of the other courtly games of competition—paintings, flowers, insects, and the like—all died out long ago, with the exception of shells and incense. These two continued to flourish, picking up new cultural symbolism and meaning along the way.

‍    The reason the “shell matching” game does not fit the standard format of mono awase described above has to do with different meanings of the word awase. The verb awaseru (合わせる) contains the sense of “oppose,” but also “compare,” and “join.” For most of the mono awase pastimes, it is the connotation of facing off that comes into play. In the case of the shells, however, the basic tenet of the game and the resulting symbolism that carried on historically, comes from the other sense of awase, “joining.” The two sides of a bivalve shell click into one another in a perfect fit—and only do so with their other half—a subtle but unmistakable fact not visible to the eye but confirmed by touch. The players in a game of kai awase may be competing, but the shells themselves are not. The object of the game of kai awase, in whatever form it may take, is to join the pairs. 


‍   Playing the game


From the start, shell-matching was most popular among women and girls. This is another aspect of the game that makes it different from all the other mono awase pastimes, which were not limited to one gender. The shells used were those of surf clams, ideally from Ise Bay, of a size to fit nicely in a girl’s hand. They were cleaned and polished, then the interiors covered in paper and gold leaf, and decorated with scenes from nature, or often, from the Tale of Genji. The same picture was painted on both halves of the shell on the inside. The outsides of the shells were polished, but undecorated. Unlike the other mono awase contests, which were judged on straightforward aesthetic terms, there was a deeper metaphysical meaning encoded in the shell game. The half shells were separated into two groups, symbolizing heaven and earth. Placing the shells in front of you, hinge-side closest, the right-hand half was earth, the yin side, called the dashigai (出貝, shells to be played); the left-hand side was heaven, yang, called the jigai (地貝, the fixed-in-place shells.) They were placed in separate containers called oke ()—octagonal lacquered boxes with woven silk cords. 

In its most elaborate form, this version of the game consisted of 360 pairs of matched clam shells, a number that mirrored the average number of days in a year according to the astronomical almanac. Like the other, more established mono awase pastimes, the game was very social, usually played by twenty players. 


‍   Setting up the game


The yang jigai were arranged, face down, in the following manner. Twelve of these half shells, symbolizing the twelve months, were set in a circle, along with seven more, representing the days of the week. The resulting number 19, represented the metonic cycle in which the moon returns, in the same phase, to the same longitude in the sky. The remaining shells were arranged in nine more or less equal lines, representing the nine layers of heaven. Now the game begins. The first player takes a yin dashigai from the other container and places it in the center, face down. The remaining players, sitting in a circle around the shells, take turns trying to match this shell with its jigai mate. They do so by looking at the natural, unpainted outside of the facedown shells—all sporting very similar subtle narrow stripes of beige and brown.

‍    The player holds the dashigai that is being played in her hand, still face down, covering it with her kimono sleeve. After choosing a jigai, she picks it up—also face down—and slides it on top of the dashigai in her hand. If the halves do not click together, she simply returns the jigai to its place. If it is a mate, however, it will click in place, and she knows, without looking that she has a match. Now she can take the two halves out and hold them up to show the painted interiors to the other players. They will see at a glance that the pictures match. No cheating possible here! She may be permitted to choose another dashigai from the container, and try again, or simply hold her pair while play moves on to the next person. This manner of playing is why the game was also called kai ooi (貝覆いor “shell-covering.”) The winner is she who, at the end, has the most paired shells.


Historical changes in kai awase


By its very nature, the concept of matching shells was amenable to various changes and simplifications. One version was to paint the shells with two parts of a famous poem, and have the goal be the uniting of the poem, or even have one side be a portrait of the poet, the other the poem they composed. This function was later taken by cards (karuta), most famously the Hyakunin Isshū collection of one hundred poems by one hundred famous poets.  The card version of this game soon superseded the shells, and is still played today. It is a traditional New Year’s pastime. Another simplified version, which likely used fewer shells, was to simply turn all the shell halves face down then take turns flipping them over, two at a time, to find a match. If no match, the shells are put back in place and the next player gets a turn. The better one can remember where particular pictures were located, the more successful they would be in finding pairs. Whoever ended up with the most matched pairs is the winner, on the same principle as our card game Concentration. This version could also be made more sophisticated by requiring the player who makes a pair to compose a poem on the subject depicted on the shell.

‍    The objects put forth for comparison in most mono awase competitions (with the possible exception of poems that might be preserved in anthologies) were ephemeral. Two branches of flowering plum offered for consideration; two paintings evaluated for the emotions they evoked; two rhizomes of calamus sporting long filaments of rootlets; two painted dancing fans. The focus of intense appreciation for the moment, these things were probably cast aside when the competition was over. The sumptuously gilded and painted clamshells were a different matter. They were painstakingly crafted and valued objets d’art in and of themselves. Not only the shells, but the paired containers (always a pair) to store the two halves of the shells, were examples of fine lacquer often with elaborate inlay. Called oke—literally a “tub”—these kai oke became precious objects, heirlooms, and eventually an essential item in an aristocratic bride’s trousseau.

‍    By the Muromachi period (1336-1575), even as the courtly world of the nobility was overshadowed by the military world of the shoguns, the fashions of the aristocrats often seeped into the culture of the samurai class. The custom of endowing a bride-to-be with a set of shells was one such custom, although the octagonal gold and inlaid lacquer boxes might instead be made of polished black lacquer with an elegantly simple family crest. The sets of shells had a prominent place in the ceremonial procession from a bride’s family home to that of her new husband. The chief retainer of the bride’s father oversaw transporting the tubs and presented them to the groom’s family in an evening ceremony known as the kai oke watashi(貝桶渡し)the “presenting of the shell tubs.”


Women and clamshells


Is it an accident that clams became so closely associated with women? The sexual innuendo that compares a clam with female genitalia hardly needs mention. In other ways too, clams and their shells whispered to women alone. Failing to match the shells too many times was thought to hint at a possible moral failure. In this way, for the girls who played, the shells were perhaps more than just a game. “A virtuous woman does not give herself twice” was one of the moral injunctions for women of the samurai class. In other words, like the shells, which have one match and one only, a woman should cleave to her husband, even when widowed. The shells were the perfect symbolic embodiment of this injunction.

During the Edo period (1603-1868), the elaborate tubs of shells may have been de rigueur dowry items for the wealthy, but their symbolism was too valuable to limit to the upper classes alone. Miniature replicas of the shell tubs became standard items in the set of figures for the Girls’ Day array of imperial dolls and courtiers. They are still seen today as essential parts of these displays. More recently, some modern/traditional wedding ceremonies have now incorporated an exchange of painted half shells as part of the ceremony, in which bride and groom take up the shells and pair them in front of guests. Renditions of painted shells and their tubs are also a popular felicitous motif in kimono and ceramic design.

‍   At present, one can find scattered random painted shells in antique shops, homes, and even E-bay. Full antique sets are extremely rare. Most modern Japanese mistakenly think that the shell matching game involved matching the painted images, rather than the natural outside of the shell. In 1999, when I was in Kyoto doing research for The Tale of Murasaki, I was able to attend a gathering sponsored by the local Murasaki Shikibu Appreciation Society, in which we were taught to play the full 360-count shell traditional game. All the ladies (it was an entirely female group) appeared surprised that we were expected to use the natural shell backs as the basis of comparison. All of a sudden, what had seemed a childish amusement, no matter how lovely, became a difficult challenge.







Author holding what appears to be a failed match…