Previous answer is
Mumei (attributed to Den Hosho).
無銘(伝　保昌)

Special feature: Hosyo school is Sadamune, who lived in Takaichi County, Yamato Province. Sadayoshi, who is known for having the skill of Sadayoshi, Sadakiyo, and Sadaoki, has Bunpo and Kareki. The age of Gentei and others can be seen, and the activity and age of the group are clear. Their work shows Jigane's total straight grain training. The stem is covered with a higaki file, showing outstanding individuality among the five
Yamato schools.

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Appraisal Quiz #805 (July 27th, 2024)
Who made this sword do you think ?
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Blade Length: 68.1 cm (26.81 in)
Curvature: 1.8 cm (0.71 in)
Mekugi Hole: 3 (2 filled)
Width at Base: 2.79 cm (1.10 in)
Width at Tip: 2.01 cm (0.79 in)
Thickness: 0.43 cm (0.17 in)
Sword Weight: 620 grams
Shape: Standard width and thickness.
The sword has a deep curvature and a standard tip.
There remains a red inscription on the tang.
Jigane: A tightly forged jigane and utsuri appearing.
The fine, clear surface can be seen.
Hamon: Small nie-deki suguha with small ashi and active ha.
The boshi is notare and returns in komaru.

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Answer will be posted at next Appraisal Quiz.

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