A Sword Decorated with Mother of Pearl Inlay (said to Have

Raden-Decorated Ceremonial Sword (Said to be Offered by Komatsu Shigemori)

Hidden among the towering camphor trees of Omishima Island, in the inner sanctuary of Oyamazumi Shrine, rests one of Japan's most exquisite testimonies to the refined aesthetic of late Heian aristocratic culture: the Raden-Decorated Ceremonial Sword (Raden-kazari-tachi), traditionally said to have been offered by Komatsu Shigemori, better known as Taira no Shigemori. Designated a national Important Cultural Property in 1901, this dazzling court sword bridges the worlds of imperial ceremony, samurai legend, and sacred devotion at the shrine revered as Japan's "General Guardian Deity."

Unlike the battle-tested swords of the warrior class, the kazari-tachi was a ceremonial weapon designed exclusively for the most elevated court rituals. Glittering with mother-of-pearl inlay (raden) and rich lacquer work, this treasure embodies the courtly grace of an era when the Taira clan stood at the pinnacle of power, just before the dawn of the samurai age.

Historical Background

The kazari-tachi, or "decorated sword," was the most prestigious form of ceremonial blade in Heian-period Japan. Permission to wear one was reserved by imperial decree for nobles holding the rank of Sangi (Imperial Adviser) or above, including the Imperial family itself. Crafted with sheaths of rare imported woods such as rosewood, these swords were embellished with gold, silver, and the lustrous shimmer of raden — a technique in which thin slices of abalone or turban shell are inlaid into wood or lacquer to create luminous patterns. Because they were intended solely for ritual use, the sheaths often contained not a true blade but a thin strip of iron or a wooden core finished in lacquer, known as an urushi-tachi.

The traditional donor of this sword, Taira no Shigemori (1138–1179), was the eldest son of Taira no Kiyomori, the powerful warlord who effectively ruled Japan in the late Heian period. Shigemori distinguished himself in the Hōgen Rebellion of 1156 and the Heiji Rebellion of 1159, rising swiftly through the court ranks to reach the position of Naidaijin (Inner Minister) in 1177. Because his residence stood in the Komatsu district of the Rokuhara estate in Kyoto, he was popularly known as Komatsu Naidaijin, or "the Inner Minister of Komatsu." His estate was famed for its forty-eight lanterns, earning him the additional title of "Lantern Minister" (Tōrō Daijin).

Shigemori's connection to Ehime is more than incidental. From 1159 onward he served as Governor of Iyo Province (Iyo no Kami), the very province in which Oyamazumi Shrine is enshrined. His devotion to the deity of Mishima Daimyōjin, guardian of the Inland Sea routes vital to Taira maritime power, made the offering of a sword befitting his court rank both a political statement and an act of profound piety. The Tale of the Heike portrays Shigemori as a man of unusual virtue — calm, learned, and devoted to Buddhist principles — who often counseled restraint to his strong-willed father.

Why It Was Designated an Important Cultural Property

The Raden-Decorated Ceremonial Sword was officially designated an Important Cultural Property of Japan on March 27, 1901, in the early Meiji-era wave of cultural protection legislation. Several layers of value combine to make this designation richly deserved.

First, surviving examples of authentic late-Heian kazari-tachi are extraordinarily rare. The genre flourished briefly among the highest aristocracy and was largely supplanted by warrior-class sword fittings as the medieval era progressed. Each surviving piece is therefore an irreplaceable record of court craftsmanship at its zenith.

Second, the raden technique applied here represents one of the most demanding decorative arts of the Heian period. The patient labor of cutting, polishing, and embedding iridescent shell fragments into wood or lacquer demanded both technical mastery and refined artistic sensibility. The result, when light catches the shell at oblique angles, produces a shimmer that Heian poets compared to moonlight on water.

Third, the traditional attribution to Taira no Shigemori adds an irreplaceable historical narrative. Whether or not modern scholarship can verify every detail of the legend, the persistence of the tradition at Oyamazumi Shrine — an institution that meticulously preserved its donor records across centuries — speaks to a deep historical memory linking the Taira clan to this sacred site.

Highlights and Points of Interest

For visitors who make the journey to Omishima Island, the Raden-Decorated Ceremonial Sword offers several distinctive points of fascination that reward close observation.

Visitor Information

Oyamazumi Shrine sits on the western shore of Omishima, an island accessible via the scenic Shimanami Kaidō expressway connecting Honshu and Shikoku. The Treasure Hall complex, where the Raden-Decorated Ceremonial Sword is displayed, opens daily from 8:30 a.m. to 5:00 p.m., with last admission at 4:30 p.m. A combined entry ticket grants access to both treasure halls and the adjacent Maritime Museum. Photography inside the halls is prohibited, preserving both the dim lighting essential to artifact preservation and the meditative atmosphere appropriate to a sacred site.

The shrine grounds themselves are a destination of great beauty. A grove of ancient camphor trees, designated a National Natural Monument, surrounds the worship hall, with one giant specimen said to be approximately 2,600 years old. Walking among these towering trees before or after a visit to the treasure halls offers a contemplative pause that complements the experience of viewing centuries-old craftsmanship.

Surrounding Attractions

Omishima offers several worthwhile destinations within easy reach of the shrine. The Tokoro Museum and Toyo Ito Museum of Architecture, both within the same island, attract design enthusiasts from across Asia. The Oyamazumi Shrine Okunoin (inner sanctuary) lies a short walk through forested paths, passing the famous Iki-ki no Mikado, a "living tree gateway" formed by a hollowed camphor trunk. Cycling along the Shimanami Kaidō, which links Omishima to neighboring islands, provides spectacular views of the Seto Inland Sea, dotted with the island chains that once formed the heartland of the Murakami pirates — a maritime culture intimately tied to the shrine. Local restaurants serve the island's famous citrus produce and fresh sea bream, offering a taste of the Setouchi region's bounty.