Previous answer is
Bishu Osafune Yasumitsu
Dated: August, 1440 (Eikyo 12)
備州長船康光
永享十二年八月日

Features: Bishu Osafune Yasumitsu is considered one of the representative swordsmiths of the Muromachi period, along with Morimitsu and Yasumitsu.
This piece is dated August 1440. At that time, long swords such as this were extremely rare for Morimitsu and Yasumitsu, who mainly produced shorter wakizashi.
This long sword features an older tachi-mei signature style, preserving the characteristics of that era.

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Appraisal Quiz #875 (November 29th, 2025)
Who made this sword do you think ?
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Blade Length: 73.0 cm (28.74 in)
Curvature: 1.5 cm (0.59 in)
Mekugi Hole: 3
Width at Base (Motohaba): 2.89 cm (1.14 in)
Width at Tip: 1.8 cm (0.71 in)
Thickness of rim (Kasane): 0.54 cm (0.21 in)
Sword Weight: 645 g
Shape: A sword with standard width and thickness, and a slightly curved shape.
Jigane: Itame hada with visible chikei and mokume hada, appearing similarly on the shinogi-ji as well.
Hamon: Nie-deki, gunome-midare with active kinsuji. The boshi is midare-komi with a hakikake finish

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