Long Sword (Tachi), Signed "Yasukiyo

Early Bizen swordmaking before the middle of the Kamakura period (1185-1333) is known as Old Bizen. The characters, Yasukiyo, are inscribed on the front surface of the tang of this long tachi blade. The small tip has no turn-back; the blade surface between the temper line and the ridge appears whiteish and misted over with an irregular pattern; and the temper line alternates clove-shaped waves (J., chôji midare) with undulating patterns (J., gunome). These features, reflecting the typical Old Bizen style, suggest that Yasukiyo was active in Bizen (present-day Okayama Prefecture). However, since his name does not appear in directories or other lists of swordsmiths, one theory holds that he worked in Hôki (Tottori Prefecture).

— Museum description: Kyoto National Museum (CC BY 4.0), via ColBase / Japan Search.