* Image is for illustrative purposes only.Ōkanehira
大包平
Also known as: Ōkanehira · Yokozuna of Japanese Swords · Tokyo University of Swords · Supreme Tachi of Miraculous Lightness
Description
Overview
Okanehira is a tachi forged by Kanehira, a smith of the Ko-Bizen (Old Bizen) school active in Bizen Province (present-day Okayama Prefecture) in the late Heian period. A National Treasure and one of the supreme masterpieces of the Japanese sword, it is also called "the yokozuna of Japanese swords." Though a magnificent great sword with a blade length of two shaku nine sun four bu (about 89.2 cm), its defining feature is that it was made astonishingly light yet strong by forging the blade thin. This high union of size and lightness, of the practical and the beautiful, is regarded as a miracle of forging technique, said to be difficult to reproduce fully even with modern metallurgy.
Style and Characteristics
The smith Kanehira belonged to the Ko-Bizen school and is famed as its finest maker. Ko-Bizen (Old Bizen) is the collective name for the Bizen smiths of the late Heian to early Kamakura period, before the rise of the Osafune school — the dawn-era masters who produced such makers as Tomonari and Masatsune. Reliably signed works by Kanehira are few, but Okanehira is regarded as the foremost masterpiece among them. The ji-hada is a finely packed ko-itame with minute ji-nie; the steel is clear and lustrous, and the midare-utsuri characteristic of the Bizen tradition stands out vividly. The hamon is a dignified ko-midare mixed with ko-choji, with a tight, clear nioi-guchi and abundant ashi and yo. The boshi turns back in ko-maru, and the tang is ubu with the long signature "Bizen no Kuni Kanehira saku," and cutting so full a signature on a great sword of this size is itself unusual. The curvature is a somewhat shallow 3.5 cm; the strong koshizori and firmly grounded stance are typical of the late Heian tachi, but the broad body and grand form were exceptional for the age, revealing Kanehira's individual aesthetic. The "O" (great) of "Okanehira" is said to have been added to distinguish this especially superb blade among the other works of Kanehira.
Designation and Holdings
Okanehira was designated a National Treasure in 1951. Its provenance traces back to its acquisition by Ikeda Terumasa, lord of Himeji domain in Harima, after which it was treasured as an heirloom of the Ikeda family of Okayama domain, together with noted blades such as the Ikeda Masamune. In 1967 the blade was purchased by the Ministry of Education (as it then was) for 65 million yen and placed in the Tokyo National Museum. This was an exceptional valuation for the time, said to correspond to roughly 260 million yen in today's money, and it is held by the museum still. At the museum, for its technical perfection, it is sometimes ranked with the celebrated "Dojigiri Yasutsuna," also in the collection, as "the two yokozuna of East and West." With the museum's "Mikazuki Munechika" it is often paired as a contrast of grace and grandeur. Where Mikazuki Munechika embodies courtly, elegant beauty, Okanehira is seen as the summit of technique uniting grandeur and refinement, and the contrasting appeal of the two blades has long been discussed.
Anecdotes and Provenance
The name "Okanehira" is said to prefix the "O" (great) to distinguish this incomparable masterpiece among the other surviving works of Kanehira. True to that name, it carries a commanding length of about 89 cm yet weighs a strikingly light 1.35 kg — uniting size and lightness, grandeur and refinement in a single blade, which is the reason later ages hailed it as "the yokozuna of Japanese swords." As for its descent, it began with the acquisition by Ikeda Terumasa, lord of Himeji, and was guarded as the foremost treasure of the house even after the Ikeda were transferred to Okayama, passing down through the Meiji, Taisho, and Showa eras within the family. In 1967 it became national property through purchase by the Ministry of Education (as it then was) and entered the Tokyo National Museum, becoming a national treasure that the wider public can now encounter face to face. This passage — from a warrior house's heirloom of several centuries to a treasure of a public museum — mirrors a facet of modern sword history, in which the Japanese blade shifted from a privately held prize to a cultural property belonging to all.
Legends & Stories
## Legend and Anecdotes The greatest mystery and greatest allure of Ōkanehira lies in its remarkable lightness. Despite being a large tachi with a blade length of approximately 89 cm and a width at the base of approximately 3.7 cm, it weighs approximately 1.35 kg (about 1350 g), making it remarkably light for a large tachi of comparable size. Typically, a tachi of such length and proportion exceeds 2 kg, but Ōkanehira achieves a sophisticated balance between length and lightness through thin construction, earning high praise as a testament to exceptional forging skill. Despite its thin kasane (cross-section), it maintains superior strength and excellent balance of weight distribution, resulting in a blade that feels even lighter than its specifications suggest and is exceptionally easy to wield. Ikeda Terumasa (1565–1613) was a feudal lord who served Oda Nobunaga, Toyotomi Hideyoshi, and Tokugawa Ieyasu, and was rewarded with Himeji Domain in Harima with a revenue of 520,000 koku for his deeds at the Battle of Sekigahara. The precise circumstances of how and when Terumasa acquired Ōkanehira remain unclear, but his ability to possess such a magnificent blade reflects his power and wealth. Subsequently, even after the Ikeda family was transferred to Okayama Domain, they maintained this tachi as their most prized family treasure. The practical significance of Ōkanehira's lightness is equally important. Its remarkable lightness of approximately 1.35 kg combined with excellent weight distribution, despite being a large tachi of approximately 89 cm in length, enabled it to retain the overwhelming reach of a large tachi while offering the handling ease of a standard tachi, demonstrating that it was one of the ideal weapons on the battlefield. It is this perfect union of functionality and artistry that establishes Ōkanehira as the "Yokozuna of Japanese Swords." When displayed together with Mikazuki Munechika at the Tokyo National Museum, the contrast between the two is often described as "Beauty and Craft," "Elegance and Robustness," and "Imperial Court and Warrior Culture." While Mikazuki Munechika embodies the aesthetic sensibilities of Heian nobility, Ōkanehira represents the meritocratic spirit of Heian warriors. The fact that these two masterpieces reside together in the same museum is a blessing for Japanese sword culture and remains a continuous draw for sword enthusiasts from around the world.