Findings on Nerikawa Tsuba
In the fall of 2000, we visited Oyamazumi Jinja on Omishima, an island in the Geiyo straight of Japan’s inland sea. Founded in 719, the shrine houses a large grouping of Japan’s National Treasure and Important Cultural Property arms and armor. Many important items are on public display in the Shiyoden and Kokuho-kan.
Oyamazumi, the deity of the shrine, is the elder brother of Amaterasu Ominokami, a guardian of the Japanese people and a protector of sea travelers. The shrine was an important stop for those making the voyage from the western provinces to the capital and became a special site for the warrior class. Many important military figures of the Heian and Kamakura periods gave swords and armor to the shrine that have been preserved to the present day. Rather than commissioning pieces to be dedicated to the shrine, most of what was given was the actual weapons used successfully in battle. Instead of being freshly polished and remounted, the swords were presented “as-is” and for the most part have been retained as they were received. Also unusual, in part because of the location of the shrine, is that the shrine swords have not been removed for use or transferred to the personal collections of past regional strongmen.
There are fascinating swords preserved at Oyamazumi. One of the first display rooms is full of ubu naginata from the Heian and Kamakura periods. Another features a selection of ubu Nanbokucho tachi with nagasa up to six feet, and with original koshirae! There is an early blade identified as ca. 950 AD that shows features of the construction of early chokuto, but also has a distinct curvature. Surprisingly this sword escapes mention in the published discussions of the origin of the Nihonto. This article will focus on the discussion of nerikawa tsuba and the mountings of some of these early swords.
A nerikawa tsuba is a leather sword guard. The kanji for neri means to gloss, soften, polish, and appears in compound with other kanji to mean paste, plaster and hardening by kneading. Kawa is leather. Nerikawa is hardened/polished leather.
These tsuba are made of layers of thin leather laminated together. Most of the nerikawa tsuba that we see today date from the late Edo period. These late tsuba are usually rather thick and small in diameter. The web is typically covered with a glossy lacquer and rim is fitted with a fukurin to cover the cut edge of the laminated leather.
Most general books on tsuba state that nerikawa guards were in wide use in Heian and Kamakura times. The usual thinking is that these tsuba predate, and were later replaced by, the ko-Tosho style guards. The puzzling thing has been that almost no early nerikawa tsuba seemed to have survived. The few that are widely published are those thate are preserved on the koshirae of famous swords like the Kogarasu maru, Shishi maru, Oni maru, etc.. Just who made nerikawa tsuba is a puzzle. Were the workers associated with armor making shops, where leather was worked extensively? Some Keman (hanging ornaments) in Buddhist temples in the Heian era were made of lacquered hide. Hide working may have been a specialized craft in itself. Or, leather tsuba making could have been an occupation on its own.
Most of the koshirae from the Heian and Kamakura periods that we see in museums and books from Japan are fitted with various styles of metal tsuba. There are shitogi, aoi and variants done with more or less ornamentation. It is striking that most of these koshirae are quite slender and would only be capable of containing a rather slightly proportioned blade. Generally the lacquer and metal work is quite finely done. Presumably, these delicate swords are not representative of what was worn in actual battle.
While Oyamazumi does display a number of this style of koshirae, in contrast there are many more mountings that appear oversized in comparison. Of course, these koshirae are just those that are sized to fit a more robust blade. While still of fine quality, these big tachi are representative of the fighting swords of the time. Very interestingly, all of these koshirae are fitted with nerikawa tsuba. These are fairly large mokko and round shaped guards. On the finest of the koshirae, the surface is lacquered and the mimi is fitted with a fukurin. In most cases however, there is no sign of either remaining. Almost all of these tsuba have delaminated such that the separate leather sheets can clearly be seen. The number of layers used varies between three and six, although most examples are four or five layers. It is possible that the fukurin have been lost, possibly due to the shrinkage of the leather over time. I suppose that it is also possible that lacquer could be lost as well, although this seems unlikely given that the lacquer of the saya were well preserved, as were may of the handle wraps. It seems possible however that these tsuba may never have had lacquer or fukurin, but were simply glued together.
The present condition of these guards holds the explanation for how we don’t see examples of what was the dominant tsuba style of the time. Any that survived initial use simply fell apart. The only reason that these guards are still preserved is because they are still “threaded” on the nakago of the sword they were first mounted on hundreds of years ago. The unique aspect of Oyamazumi is that these swords were donated as-is, directly from use, and then left undisturbed. No doubt most swords that were carried regularly, even not in battle, would have worn through many sets of mounts. Certainly these nerikawa tsuba would have worn out quickly and been replaced regularly. Any individual tsuba that were preserved would presumably have delaminated as these did many years ago. Most swords that survived battle and remained in the family collection would have been remounted, and again the nerikawa tsuba would be lost.
Obviously only those swords that have survived use have the potential to be put away and handed down through the generations. I suspect that the overwhelming majority of fighting swords were used up rather than preserved. Those that were preserved but still serviceable were generally, modified, remounted, polished, etc., at later times.
Presumably, the use of a light weight leather tsuba vs. a heavier iron one would shift the weight distribution of the sword to a degree that it would require compensation in blade or mounting design. Interestingly none of the tachi on display at Oyamazumi are fitted with iron tsuba. If Ko-Tosho and Ko-Katchushi type tsuba were ever used on tachi, none found their way to this shrine.
#79 Raden kazari tachi ca 1166
#84 Kurourushi tachi, ca. 950 w/2 piece metal guard
#82 kawazutsum tachi ca 1190 nerikawa – fancy koshirae in lacquer
#88 yamagane zukuri kawaztu?? Tachi, Minamoto Yoshitusne, 1185, plain nerikawa
#81 Shakudozukuri tachi. Minamoto Yoritomo 1190, nerikawa w/dark fukurin
#85 Kawa Zutsumi tachi, ca. 1250. 3 layer nerikawa, no fukurin, very large koshirae
#80 Kawa Zutsumi tachi, Ouchi Yoshitaka 1250, 5 layer nerikawa
#130 Tame nerikawa zutsumi O dachi, Iyonokami kuno Michiari. 3 layer nerikawa
Rack of swords with 4-5 layer nerikawa, ~20 examples
One 6 layer nerikawa