Iron tsuba of round form with design of hatchet, snowflake, and triple diamond in openwork (ko-sukashi), and inlaid with five concentric circles of brass dots (ten-zōgan) and brass inner circular line. Sukashi elements outlined in brass.
Late Muromachi period. Diameter: 82.4 mm; Thickness: 3.0 mm The triple lozenge (or diamond) is similar to the one on TSU-305 from Sasano Collection # 15. Very old motif; as Sasano remarks in his book "...represents the unstable political situation at the time".Kokusai Tosogu Kai 5th International Convention & Exhibition, October 28-30, 2009 at NEZU Museum, Tokyo, Japan, on page 83 provides the following explanation of the triple diamond symbol: "The pine bark is the form of the Diamonds, "Bishi", mon, seen from Nara period, found on cloth stored in the Shoso In, and used primarily by the Takeda family. The form of Bishi mon [similar to ours] is called "Chu Kage Matsukawa Bishi", (Middle Shaded Pine Bark Diamond)."
A combination of hatchet (usually an axe) and a triple diamond (Matsukawabishi) alludes to the Nō play Hachi-no-ki (ref: Iron tsuba. The works of the exhibition "Kurogane no hana", The Japanese Sword Museum, 2014; AND Sasano: Japanese Sword Guard Masterpieces from the Sasano Collection. By Sasano Masayuki. Part One. Published in Japan in 1994.
The same interpretation of the said heart-like symbol (aoi leaf) is given at Helen C. Gunsaulus. Japanese sword-mounts in the collection of Field Museum. // Publication 216, Anthropological Series, Volume XVI; Chicago, 1923; p. 54: "This mokkō-formed tsuba recalls the aoi form, perforated as it is with the four aoi leaves." It is possible that the "wild boar's eye" theory was developed by later scholars.
There is also a theory, supported by Graham Gemmell, saying that: “In simple terms Onin works are decorated Ko-Katchushi tsuba. … But, not content with iron alone, they began to decorate it with what was, in the early Muromachi period, a rare and valuable metal, brass. The Onin workers cut the design into the iron, using narrow channels, cast the brass, piece by piece, and then hammered it into the iron plate as though they were putting together a jigsaw. When complete the tsuba would be black lacquered exactly as the plain iron ones had been, the brass shining dully through it in a way that fulfilled the goal of shibui or restrained elegance.” [Tosogu. Treasure of the samurai. Fine Japanese Sword Fittings from The Muromachi to The Meiji Period, by Graham Gemmell. // Sarzi-Amadè Limited, London, 1991. An exhibition held in London from 21st March to 4th April, 1991]. The following illustration from Helen C. Gunsaulus. Japanese sword-mounts in the collection of Field Museum. // Publication 216, Anthropological Series, Volume XVI; Chicago, 1923; pp. 43 supports the idea.
Helen C. Gunsaulus' description of the dragonfly emblem is as follows: "This motive, the dragon-fly (akitsu), is generally accepted as a symbol of the kingdom of Japan, and the origin of the idea is traced to the legend recounted in the Kojiki and Nihongo of the Emperor Jimmu's view of the island from mountain top. He is said to have thought the kingdom looked like a dragon-fly touching its tail with its mouth. From this it received its name Akitsu-shima... etc."
English translation of the book indicated above Nihon Tō Kōza, Volume VI, Part 1 by Harry Afu Watson, AFU Research Enterprises, Inc., 1993. Tsuba in question illustrated on page 14 and described as follows: " Tsuba mumei Ōnin. Tetsu ji maru gata ko-sukashi tsuchime shitate shinchū suemon ten zogan maru mimi. Brass suemon". My question remains: why such a text is called 'translation' while it looks more like transliteration of romanization? 