Katana
mumei Ko-Aoe (古青江)
(NBTHK Juyo-Token)
This valuable piece from the middle Kamakura period has a blade length of 30.3 inches (76.4 cm) and shows a clear blade curvature of 0.7 inches (1.9 cm). The handle (nakago) has been shortened and has 2 tang holes. The width at the hamachi (motohaba) is 1.1 inches (2.80 cm), while the width at the kissaki (sakihaba) is 0.7 inches (1.8 cm). The blade spine (mune) is iori-mune and the blade thickness (kasane) at the spine is 0.3 inches (0.7 cm).
The forging structure (kitae, jitetsu) shows an itame structure with mokume and standing "chirimen-hada", characterized by many chikei and jifu-utzuri. The hamon is a suguha pattern mixed with ko-midare, ko-choji, ko-ashi and yo in ko-nie-deki and shows hotsure, fine kinsuji and sunagashi. On the root side (Ura side) of the blade is a koshibi-Horimono. The weight of the Katana is 2 lbs (900 g) and it was certified in the Juyo session of the NTHK in 2000.
The mounting (koshirae) is a shira-saya. This Katana has been referred to as "an exceptional masterpiece" and was illustrated in "Swords of the Nihonto Club Germany 2" by Markus Sesko (2013, Lulu, ISBN 978-1-300-91985-8).
According to tradition, the Bitchû-Aoe school was founded by Yasutsugu (安次) around Jô´an (承安, 1171-1175) and flourished until the end of the Nanbokuchô period, with works and smiths classified as "Ko-Aoe" from the end of the Heian to the middle Kamakura period. Their style is characterized by a kitae with a prominent mokume that appears as a so-called "chirimen-hada" and usually mixed with jifu.
The hamon is a calm suguha-chô that can also be mixed with ko-midare, but is always relatively nie-intensive. Unlike contemporary Bizen works, Ko-Aoe works give a more reserved, calm, but very elegant impression.
This blade shows an itame mixed with mokume that stands out overall and appears as chirimen-hada. It shows ji-nie, much chikei and a jifu-utsuri. The hamon is a suguha mixed with ko-midare, ko-chôji, ko-ashi and yô and is hardened in ko-nie-deki. Fine kinsuji and sunagashi can also be found.
The nioiguchi is rather suppressed. All in all, we have here the typical characteristics of the Ko-Aoe school very clearly. Despite the ô-suriage, the blade is above-average length and retains a deep koshizori, which, combined with the abundant niku and the strong jiba, gives it an imposing appearance. A masterpiece among all the works attributed to this school.
In the middle of the blade spine is a strong battle scar.