Bronze Mirror (excavated from the Usa Akatsuka Tomb in Buzen

Bronze Mirrors Excavated from Akazuka Kofun, Buzen Province: A Window into Japan's Dawn

Housed at the Kyoto National Museum, the five bronze mirrors excavated from Akazuka Kofun in the former Buzen Province (modern-day Usa City, Oita Prefecture) are among the most historically significant archaeological finds in Japan. Designated as an Important Cultural Property, these mirrors date to the 3rd century — the dawn of the Kofun (Tumulus) period, an era when a new political order was emerging across the Japanese archipelago. For travelers fascinated by the mysterious origins of Japanese civilization, the legendary Queen Himiko, and the spread of Yamato power, these modest-looking disks of cast bronze are nothing short of treasure.

Historical Background

Akazuka Kofun is a keyhole-shaped burial mound about 57.5 meters long, located on a plateau in the Takamori area of Usa City. Although modest in size compared with the colossal kofun of the Kinki region, Akazuka is widely regarded as one of the oldest keyhole tombs in all of Kyushu, built in the late 3rd century — a pivotal moment when the Yamato polity was extending its cultural and political influence outward from central Japan.

In the autumn of 1921, the rear circular portion of the mound was opened and a box-shaped stone coffin was revealed at its center. Inside, five bronze mirrors had been carefully propped up against the coffin walls, as if arranged to encircle and protect the deceased. Alongside them were tubular jade beads (kudatama), fragments of iron swords, and iron axes. The elegant positioning of the mirrors — standing rather than laid flat — suggests they served not merely as personal possessions but as sacred ritual objects meant to accompany a person of great status into the afterlife.

The excavation report, later compiled by the eminent archaeologist Umehara Sueji, caused a sensation in academic circles. Akazuka suddenly became a name known to every student of early Japanese history.

Why These Mirrors Matter: The Reason for Designation

The five mirrors are a remarkable group. Four are triangular-rimmed deity-and-beast mirrors (sankakubuchi shinjūkyō), a distinctive type decorated with images of Chinese immortals and mythical animals around a central knob, while one is a related triangular-rimmed dragon-and-tiger mirror. Scholars generally classify them as imported mirrors (hakusaikyō), believed to have been brought to Japan from the continent.

Their true significance, however, lies in a subtle archaeological detail: several of the Akazuka mirrors are "same-mold mirrors" (dōhankyō) — cast from the very same clay molds as mirrors unearthed at other famous tumuli, including Ishizukayama Kofun in Fukuoka, Tsubaiōtsukayama Kofun in Kyoto, and Tsutsuno Kofun in Mie. In other words, they are siblings to mirrors buried for kings and chieftains hundreds of kilometers away. This distribution pattern is one of the strongest pieces of evidence that the early Yamato rulers forged alliances with regional chiefs by gifting prestigious mirrors — and that Usa's ruler was an early and important partner in this network.

For this reason, the Akazuka mirrors are central to the great debate over Queen Himiko of Yamatai, the shaman-queen who, according to the Chinese chronicle Wei Zhi (Gishi Wajinden), received one hundred bronze mirrors from the Wei court in 239 CE. While scholars continue to debate whether triangular-rimmed mirrors are truly those legendary gifts, the Akazuka find remains one of the most important data points in that centuries-old mystery.

Highlights: What to Look For When Viewing the Mirrors

When the mirrors are displayed at the Kyoto National Museum, visitors can appreciate details that may not be obvious at first glance. The decorated back of each mirror features a triangular cross-section along the rim — the feature that gives this mirror type its name. Arranged around a central knob (chū) used to thread a cord, you can see reliefs of seated deities and crouching mythical beasts, drawn from the Taoist-inspired imagery of Han- and Wei-dynasty China.

The mirror surface itself — the polished, slightly convex bronze face — was originally lustrous enough to reflect the viewer clearly. In the Yayoi and Kofun periods, such reflective surfaces were considered almost magical, suitable as ritual tools to communicate with the gods.

Pay attention to the pairings. When multiple mirrors from Akazuka are shown together with examples from other tumuli, you may notice that some are almost identical — these are the famous same-mold mirrors, silent testimony to the political ties that once bound distant chiefs together.

Visitor Information

The mirrors are part of the collection of the Kyoto National Museum, located in the Higashiyama district of Kyoto. The museum is one of Japan's four national museums and houses roughly 14,000 objects, including many National Treasures and Important Cultural Properties. The Heisei Chishinkan wing features rotating themed exhibitions of archaeological and art objects, while the historic Meiji Kotokan — a red-brick Meiji-era building from 1895, itself an Important Cultural Property — hosts special exhibitions.

Because the mirrors are fragile ancient metal objects, they are not continuously on display. Travelers hoping to see them in person are encouraged to check the museum's exhibition schedule in advance, particularly for themed exhibitions on archaeology or the Kofun period.

• Access: A short walk from Shichijo Station on the Keihan Main Line, or from the "Hakubutsukan Sanjūsangendō-mae" bus stop
• From JR Kyoto Station: about 10 minutes by city bus (routes 100, 206, or 208)
• Open Tuesday through Sunday; closed on Mondays (closed the following day if Monday is a national holiday)

Surrounding Attractions

The museum sits in one of Kyoto's most rewarding sightseeing districts. Directly across Shichijo Street stands Sanjūsangen-dō, a long wooden hall famous for its thousand golden statues of the bodhisattva Kannon. A short walk away you will find Chishaku-in, a serene temple with nationally celebrated screen paintings, and Toyokuni Shrine, dedicated to the warlord Toyotomi Hideyoshi.

To the north, about twenty minutes on foot, lies the Gion district and the famous Kiyomizu-dera temple, a UNESCO World Heritage site. Traveling south, Fushimi Inari Taisha with its tunnels of vermilion torii gates is a quick train ride away on the Keihan line.

For those deeply intrigued by the mirrors themselves, a longer journey by train and ferry to Usa City in Oita Prefecture rewards visitors with the actual Akazuka Kofun, preserved on the grounds of the Oita Prefectural Museum of History at Usa Fudoki-no-Oka — an open park of ancient tombs where the mirrors' story began.