Guide to Appraising Bizen Osafune Morimitsu — Identifying Authentic Works of the Premier Oei Bizen Master

What Kind of Bladesmith Was Bishu Osafune Morimitu?

Bishu Osafune Morimitu (備州長船盛光) was a bladesmith who flourished in the early Muromachi period, during the Ōei era (circa 1394–1427), in Osafune, Bizen Province (present-day Osafune-chō, Setouchi City, Okayama Prefecture), and is recognized as a master craftsman who stands at the pinnacle of Ōei Bizen.

Morimitu, called alongside his contemporary Yasumitu as one of the "Twin Peaks of Ōei Bizen," elevated the Bizen tradition of the Kamakura and Nanboku-chō periods—represented by the Ichimonji, Fukuoka Ichimonji, Osafune Nagamitsu, and Kanemitsu schools—into the new aesthetic of the Muromachi age. His works are recognized today as national treasures and important cultural properties at the highest level, and serve as core research subjects in Bizen tradition authentication.

This article focuses on authentication points for distinguishing genuine works by Bishu Osafune Morimitu, and explains representative pieces, methods for distinguishing him from Yasumitu, and a catalog of extant works.

Morimitu's Jigane (Ground Steel)—The First Gate of Authentication

The jigane of Bishu Osafune Morimitu embodies the orthodox Bizen tradition with "finely packed small koitame" as its foundation. The following characteristics serve as the primary authentication points.

Texture of Itame Hada:

• The hada is finely packed with minimal graininess and has the texture of "smooth silk grain (kinuji)"
• Jinie is finely and evenly scattered, possessing "clarity without cloudiness"
• The flow of itame is regular; "disordered nagare itame" is a common sign of forgery

Presence or Absence of Utsuri: A characteristic of the Bizen tradition is "utsuri"—cloud-like or haze-like patterns appearing in the jigane. In authentic works by Morimitu, "rod utsuri (bō-utsuri)" or "faint disordered utsuri (midaré-utsuri)" frequently appears. When utsuri is completely absent, it should be considered as one factor suggesting possible forgery (however, the presence or absence of utsuri alone cannot determine authenticity).

Morimitu's Hamon (Temper Pattern)—The Heart of Ōei Bizen Beauty

Morimitu's hamon is primarily composed of "chōji-midare" (clove-petal pattern), which epitomizes the aesthetic of Ōei Bizen.

Characteristics of Chōji-Midare:

• The typical form is "soroi chōji" (aligned clove pattern), where the clove shapes are well-formed and each peak unfolds in a consistent rhythm
• "Chōji-gunome" (mixed clove and wavy patterns) is also frequently observed
• The nioiguchi is tight yet bright and refined; compared to early Kamakura period Ichimonji work, it displays "brighter flame-like quality"
• The width of the yakiba is moderate, with slight variation from hilt to point

Characteristics of Hamon Commonly Seen in Forgeries:

• When the shape of the chōji is uneven or chaotic
• When the nioiguchi is clouded or unclear
• When the yakiba width is overly uniform throughout

Morimitu's Mei (Signature)—Key Points for Confirming Script and Position

The mei is one of the most critical elements in authentication. Morimitu's signatures have the following characteristics.

Script of the Mei: The signatures "Bishu Osafune Morimitu" or "Osafune Morimitu" are most common. The script is both powerful and flowing, with individuality in the horizontal strokes of the character "Mori" and the finishing of "Mitsu." The fine details of the script are essential to learn through comparison of multiple authentic pieces, and direct observation of originals enhances authentication accuracy more than photographic materials.

Nenkimei (Dated Signatures): Many works feature dates from the Ōei era (1394–1427), and verification of date consistency is important. Works inscribed with "Ōei ○ year" serve as standard reference materials for dating.

Position and Carving of the Mei: The position of the mei on the front (omote) and back (ura) of the nakago, as well as the angle and depth of the chisel marks, also serve as reference points.

Distinguishing Morimitu from Yasumitu—Differences Between the Twin Peaks of Ōei Bizen

Yasumitu (やすみつ), Morimitu's contemporary, is constantly compared as one of the "Twin Peaks of Ōei Bizen." Here are the main points for distinguishing between them.

Characteristics of Morimitu:

• His chōji-midare has an "aligned feeling" with a consistent, rhythmic quality
• Utsuri in the jigane readily appears, and jikei (ground scenery) also manifests in fine detail
• The chōji at the edge often exhibits "atama marumi" (rounded peaks)

Characteristics of Yasumitu:

• His chōji-midare shows "elevation changes" with pronounced, dynamic variation
• The jigane is similar to Morimitu's but with a slightly "coarser, more powerful" impression
• The chōji at the edge often exhibits "sharp-pointed (togarigimi)" peaks

Distinguishing between the two requires professional authentication skill and is a frequently occurring important subject in assessments by sword preservation societies.

Extant Works and Cultural Property Designations

Numerous extant works by Bishu Osafune Morimitu are transmitted both domestically and internationally, but those receiving official cultural property designation as certain authentic works serve as the standard for reliability.

• National Treasure Designations: Multiple tachi ranked above important cultural property status exist and are held in major national museums and Shinto shrines and Buddhist temples
• Important Cultural Property Designations: Numerous important cultural properties have been designated across tachi, uchiggatana, and tantō categories, with regular opportunities for public exhibition
• Important Art Object Designations: Multiple important art objects designated before World War II exist and are transmitted in collections both domestically and internationally

Modern Evaluation and Market for Morimitu Blades

Authentic works by Bishu Osafune Morimitu receive the highest evaluation as the pinnacle of Ōei Bizen, with high-value transactions reported when offered at the Japanese sword market. Since considerable numbers of falsely signed and unsigned pieces circulate, certification of authenticity by the Japan Art Sword Preservation Society (NBTHK) is essential when purchasing or trading.

Studying Morimitu means deeply understanding the Bizen tradition—the main current of Japanese swords—and has become a subject that enthusiasts worldwide undertake as an approach to the pinnacle of Japanese sword appreciation.