Previous answer is
　 Masashige saku(Sengo)

Special feature : Tradition says that Masashige is a son or pupil of Muramasa.
His blades are very alike Muramasa’s blade. The Hamon is of uniform on both side.
And the Nakago shape is also
His blades are less than Muramasa. Because he helped his master Muramasa to make a sword.
This blade is looks like Muramasa blade. There are many Sunagashi and Tobiyaki.
In the past, 10 pieces of Masashige was designated as NBTHK Juyo Token.
This blade has also possibility to get that.

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Appraisal Quiz #651 (July 31rd, 2021)
Who made this sword do you think ?
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Blade length : 68.8 cm or 27.08 inches.
Sori : 1.97cm or 0.77 inches.
Mekugi : 2
Width at the hamachi : 2.96cm or 1.16 inches.
Width at the Kissaki : 2.26cm or 0.88 inches.
Kasane : 0.75cm or 0.29 inches.
The weight of the sword 745 grams.
Shape : O-Suriage. Wide and thick sword with deep Sori and longer Kissaki.
Jigane : Chairmen-Hada with Jinie. Utsuri is visible.
Hamon: Ko-Niedeki Suguha based. Ko-Ashi, Yo, thin Kinsuji worked.

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Answer will be posted at next Appraisal Quiz.

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