Previous answer is
　Mumei(unsigned) attributed as Naminohira
無銘(波平)

Special feature:he Naminohira school starts from the end of the Heian period
and continues until the end of the Edo period.
The sword which was made at Heian, Kamakura and Nanbokucyo period is called K -Naminohira.
From later of Nanbokucyo period is called Naminihira school.
The style is from a spectacular work to a slender work,
but both are straight-edged, small-footed,
and small-scaled Works and bullion is wrought and works of large Itame hada sometimes
Ayasugihada comes out.Satsuma's proud Jigane is Kyusyu style texture.
This sword looks Sairen and Kongo Hyoei scholll works.
Gold Ekakiji shell, Makie style.

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Appraisal Quiz #730 (February 18th, 2023)
Who made this sword do you think ?
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Blade length: 58.4cm or 22.99inches.
Sori:0.6cm or 0.23inches.
Mekugi:2
Width at the hamachi:3.22cm or 1.26inches.
Width at the Kissaki:2.11cm or 0.83inches.
Kasane:0.62cm or 0.24inches.
The weight of the sword:650grams
Shape: Shape: regular width and thickness Wakizashi.
Jigane: Niedeki Itamehada with Chikei. There are some rough parts with lots of Chikei.
Hamon: Niedeki Gunomemidare with deep Nioikuchi. Sunagashi and Kinsuji work in Ha. Tobiyaki comes in. Boshi turns back round.

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