Previous answer is
Mumei (Aoe)

Special feature: The Aoe School had been prospered at the lower reaches of the Takanashi river in Bichu province.
This katana shows distinctive feature of Aoe school though nakago has no signature
and o-suriage. The Aoe School, regarded Yasutsugu in the middle Heian period as the founder had been prospered
at the lower reaches of the Takanashi River in Bichu province.
Swordsmiths of Aoe School forged quite a few o-naginata in late Kamakura period to early Nambokucho period.
According to the Jyuyo zufu, the blade was made at Kamakura period.

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Appraisal Quiz #468 (Decenber 9th, 2017)
Who made this sword do you think ?
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Hints. ※The picture will be enlarged

Blade length :　68.5　cm or 26.96 inches.
Sori :2.4 cm or 0.94 inches.
Mekugi : 　2
Width at the hamachi : 2.76 cm or 1.08 inches.
Width at the Kissaki : 2.14 cm or 0.84 inches.
Kasane : 0.76 cm or 0.29 inches.
Shape : The blade is regular wides and thickness
with deep sori and longer kissai nice looking shape.
On both sides of the blade has Bo-hi.
Jigane :Itame hada and oo (big)itame hada mixed
with jinie attach and chikei work along with
itame hada. On the Ji, bo utsuri appear.
Hamon :Niedeki suguha and sansaku style boshi hamon.

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