* Image is for illustrative purposes only.Uguisumaru
鶯丸
Also known as: Uguisumaru, Ashikaga Shogun Family Uguisu Tachi, Master Work by Tomomari
Description
Sword Overview
Uguisumaru is a tachi by Tomomari, a master craftsman representative of Ko-Bizen in the Heian Period, bearing the signature "Bizen no Kuni Tomomari" carved into the tang. It is also renowned in Japanese sword history as a "General Family's masterpiece blade" treasured through successive generations of the Ashikaga shogun family. The elegant name "Uguisu" (nightingale) is said to derive either from the fact that the graceful form and refined jigane and hamon patterns of this tachi soothe and delight the heart like the voice of a nightingale announcing spring's arrival, or from the presence of nightingale-related decorative patterns on the tang or fittings. With a blade length of approximately 81.8 cm (about 2 shaku 7 sun), it displays the graceful form of a tachi with the deep curvature at the hilt characteristic of ancient tachi from the Heian Period.
The Work Style of Ko-Bizen and Tomomari
Tomomari was a master craftsman representing Ko-Bizen of the Heian Period, known as one of the founders of Bizen swordmaking, with his signature cutting "Bizen no Kuni Tomomari." Tomomari's swords are ancient and refined yet powerful, possessing a unique work style in which elegance pervades even their robust character. Uguisumaru is positioned as one of Tomomari's representative works, and is particularly valuable for bearing the maker's mark "Bizen no Kuni Tomomari" on the tang. However, tachi from the Heian Period have provoked considerable scholarly debate due to difficulties in examining the tang condition and authenticity. Uguisumaru has been carefully preserved as a signed work of Ko-Bizen by Tomomari.
Characteristics of the Blade
The jigane of Uguisumaru displays an iron color with itame grain mixed with mokume in a manner typical of ancient blades, with thick jigane-nie creating a powerful yet lustrous appearance. The hamon is based on small irregular patterns with well-formed ashi and ha, displaying a refined finish with bright, crisp nioi-guchi. The kisaki is small and rounded, with the tang showing ancient construction techniques. This combination of jigane and hamon typical of ancient blades is characteristic of tachi from the Heian Period, and through its form and workmanship is consistently evaluated as a Heian-period ancient blade of Ko-Bizen centered on Tomomari.
From the Ashikaga Shogun Family to the Imperial Household
During the Muromachi Period, Uguisumaru was treasured and passed down through successive generations of the Ashikaga shogun family. The Ashikaga family was known as a daimyo house particularly dedicated to sword collecting and appraisal, possessing numerous masterpiece blades including Mikazuki Munechika, Doji Kiri Yasutsuguoki, and Onikiri Kunitsuguoki. Uguisumaru is recorded as being particularly treasured among these by the shogun family. It is recorded that in 1441 (Kakitsu 1), Ashikaga Yoshinori presented it to Ogasawara Masayasu, and thereafter it passed through successive generations of the Ogasawara family (later lords of Echizen Katsuyama). In 1908 (Meiji 41), it was donated from the Ogasawara family to the Meiji Emperor, and thereafter became an Imperial Household treasure. Currently managed by the Imperial Household Agency as an Imperial Collection, it is normally not on public display, though it may be exhibited on special occasions.
The Elegant Significance of the Name "Uguisu"
In Japanese culture, the uguisu (nightingale) is an auspicious bird heralding spring and has been celebrated extensively in poetry and waka. To bestow the name "Uguisu" upon a sword demonstrates the fusion of the samurai's aesthetic sensibility and literary refinement, superimposing the freshness of spring onto the graceful form and pure iron color of the blade. This paradox of naming a weapon after a spring songbird—beauty and death, grace and rigidity, the joy of spring and the sharpness of the edge—embodies the aesthetic at the heart of Japanese sword culture.
Tomomari's Technique—The Essence of Ko-Bizen
Tomomari was a swordsmith of Bizen Province during the Heian Period (circa 10th-11th centuries) and is among the oldest master craftsmen representing Ko-Bizen. Tomomari's works rank among the highest achievements of ancient blades from the Heian Period, and his signed pieces, inscribed "Bizen no Kuni Tomomari," are carefully preserved as precious heirlooms. That Uguisumaru is a signed work by Tomomari means this tachi was crafted using the highest techniques of the dawn of Japanese swordmaking. Tomomari's style is characterized by refined, elegant small irregular hamon and carefully worked itame-grain jigane, and is considered to represent the prototype of the "ideal Japanese blade" that later Bizen smiths aspired to achieve. While detailed descriptions of Uguisumaru's hamon and jigane characteristics vary among sources, it is regarded as representing the elegant and refined typical style of Ko-Bizen from Tomomari of the Heian Period. At approximately 81.8 cm (about 2 shaku 7 sun) in blade length, it is a large tachi exemplifying the battle tachi carried at the waist by mounted warriors of the Heian Period. It is currently preserved as an Imperial Household treasure by the Imperial Household Agency, with limited public access.
The Ashikaga Shogun Family's Sword Collection
The long transmission of Uguisumaru as a "treasured tachi of the Ashikaga shogun family" demonstrates how the shogun family of the Muromachi Period valued swords as political and cultural tools. The Ashikaga shogun family collected masterpiece blades such as Mikazuki Munechika and Doji Kiri Yasutsuguoki, with the possession of such works serving as proof of the shogun's authority and prestige. The tradition that Uguisumaru was held by the shogun family indicates that this tachi received the highest appraisal among sword authorities of the time. The Ashikaga shogun family's sword collection was managed by specialized officials called "Go-koshimono-kata," and the shogun's choice to carry a particular blade carried political significance. The "elegant nightingale-like quality" evoked by the name Uguisumaru aligned with the tastes and values of the Ashikaga shogun family, which valued both martial power and cultural refinement. After being bestowed upon Ogasawara Masayasu by Ashikaga Yoshinori in 1441 (Kakitsu 1), Uguisumaru was carefully preserved by the Ogasawara family and, following its donation in 1908 (Meiji 41), has been transmitted to the imperial family as an Imperial Household treasure.
The Status of Imperial Household Property—A Tachi Transmitted Through the Imperial Family
That Uguisumaru is currently preserved by the Imperial Household Agency as "Gyobutsu" (Imperial Collection) elevates this tachi to the highest status. Gyobutsu refers to cultural properties held by the Emperor and Imperial Household, receiving protection of the highest status distinct from National Treasures or Important Cultural Properties. Among swords transmitted through the Imperial Household, the most famous example is the "Kusanagi Sword," one of the Three Imperial Regalia, and Uguisumaru likewise has been carefully treasured as occupying a special place in the long history of the Imperial House. Due to limited public access, opportunities to view Uguisumaru in person are extremely rare, though past investigations and photographs have confirmed that it retains the typical characteristics of ancient blades from the Heian Period. With the name of Tomomari, among the greatest swordsmiths, and a provenance tracing through the Ashikaga shogun family, Ogasawara family, and Imperial House—the highest-ranked owners—Uguisumaru will undoubtedly continue to be celebrated as one of the greatest treasures in Japanese sword history.
Legends & Stories
## The Origin of the Name "Uguisu" and Its Elegant Mystery There are several theories regarding the origin of the name "Uguisumaru," and this mystery deepens the sword's refined elegance. The most widely known theory is that the blade's form and aesthetic beauty are evoked through a metaphorical naming: its appearance resembles the voice of a warbler singing in spring, exemplifying the Japanese aesthetic sensibility that grounds a sword's beauty in natural beauty. Another theory offers a more concrete explanation: ornamental metalwork or decorations depicting a warbler were applied to the blade's fittings and hilt. The true origin of the name remains unclear from antiquity; records show that by the Muromachi period, the designation "Uguisumaru Tomonari" was already in use. Regardless of which theory proves correct, the name "Uguisumaru" embodies a paradoxical aesthetic sensibility unique to Japanese culture—enveloping the sword's attributes of martial force and lethal power in the image of a small bird symbolizing the arrival of spring and the joy of life. ## The Ashikaga Shoguns and Their Attachment to Famous Swords The Ashikaga shogunal house of the Muromachi period was among the finest connoisseurs of sword collecting and authentication in Japanese history. Successive shoguns competed to gather celebrated blades as symbols of authority, and the finest treasures of the realm, known as "daimotsu," were accorded a special status as the personal swords of the shogunal house. Uguisumaru was among the treasured possessions of the Ashikaga shogunal house during the Muromachi period. However, during the Yuki Campaign of Kakitsu 1 (1441), the Shinano deputy Ogasawara Masayasu distinguished himself in service to the shogunate, and Shogun Ashikaga Yoshinori granted him Uguisumaru along with a commendation. Thereafter, Uguisumaru was transmitted through generations of the Ogasawara house, which became lords of Echizen Katsuyama Castle. ## The Weight of the Name "Tomonari" The blade of Uguisumaru bears the signature "Bizen no Kuni Tomonari." Tomonari was a master swordsmith of the Old Bizen tradition who flourished in Bizen during the Heian period; ancient texts transmit that his era was around Eien (987–989). Old Bizen forms the wellspring of Bizen blade tradition, and Tomonari's works are accorded the highest esteem as a master of its earliest period. That Uguisumaru is transmitted to the present day as a signed work of Tomonari carries profound meaning: it embodies the technique of a supreme craftsman of Old Bizen. Uguisumaru exemplifies in characteristic form the endeavor of Japanese blade culture—wherein tradition and artifact sustain each other, elevating the value of great swords and transmitting them to successive generations. ## The Spring Sword That Became an Imperial Treasure After the Meiji Restoration, Uguisumaru became part of the Imperial Collection. While imperial treasures are excluded from National Treasure designation, they receive the highest degree of protection as Japan's cultural and spiritual heritage. That this blade bearing the name of the spring warbler comes down to the present day as an imperial treasure—at the apex of Japan's state and culture—symbolizes, as it were, the essence of Japanese culture: "the reverence for beautiful things." ## The Warbler's Song and the Sword's Beauty—Japanese Aesthetic Sensibility The image of the "warbler" (uguisu) embedded in the name Uguisumaru touches the very heart of Japanese aesthetic sensibility. The warbler has been beloved in Japan since antiquity as the "herald of spring" (harutsugedori). The oldest collections of poetry, such as the Man'yōshū and Kokin Wakashū, contain numerous poems celebrating the warbler, and the scene of a warbler singing in the plum blossoms is one of the most popular artistic motifs symbolizing Japanese spring. To bestow upon a blade the name "warbler" is to grant a weapon—the instrument of death—a poetic and refined dimension, exemplifying the cultural sophistication of the warrior. From the Heian through the Muromachi periods, samurai culture embodied a coexistence of martial directness and yearning for the elegant culture of the court nobility. To name a celebrated blade with an elegant appellation was a symbolic act demonstrating that a warrior was not merely a combatant but a cultured human being. The name Uguisumaru embodies precisely this aesthetic—Japan's unique fusion of martial prowess and refined elegance. ## What the Ancient Bizen Sword Tells of the Origin of Japanese Blades Uguisumaru, transmitted as a work of Bizen Tomonari, stands near the "origin" of Japanese blade culture. The Heian period in which Tomonari lived was an era in which the fundamental form of the Japanese sword—a curved blade with a single edge and keen sharpness—became established. The transition from the straight swords of earlier times to the curved blade (wankatana) style that continues to the present was achieved through the technical investigations of swordsmiths such as Old Bizen's Tomonari. As a signed work of Tomonari, Uguisumaru is counted among the finest masterworks of the earliest period in which Japanese blade form became established. As the point of departure for Japanese blade culture, which has developed continuously over more than a thousand years thereafter, the significance of an Old Bizen sword is incalculable. In modern times, sword researchers continue to regard the techniques of Old Bizen and Tomonari as the foundation of Japanese blades, and Uguisumaru serves as an important reference point in such research. ## The Modern Evaluation of Uguisumaru In the modern era, Uguisumaru remains a signed work of Tomonari, a master craftsman epitomizing Old Bizen, and as a blade bearing the provenance of the Ashikaga shoguns, the Ogasawara house, and the Imperial Court—of the highest distinction—it occupies a special place among Japanese sword enthusiasts and history lovers. In the blade game "Touken Ranbu," Uguisumaru also appears as a popular character, depicted as an elegant figure bearing the name "Uguisumaru," and thereby the sword's name has become widely known to younger generations. While the nature of imperial treasures limits public exhibition of the actual blade, the form of the sword can be known through photographs and reference catalogs, and scholarly research reports continue to accumulate. More than a thousand years after the Heian period, the people of modern Japan likewise hear in the name Uguisumaru the voice of the spring warbler, and in Tomonari's technique perceive the spirit of Old Bizen—this continuity of aesthetic receptivity is itself one of the most distinctive aspects of Japanese blade culture.