Previous answer is
Muramasa

Special feature : Muramasa is a swordsmith at Ise Kuwana province. The blades forged by Muramasa are very famous as  ‘Yoto Muramasa’ (as a meaning of ‘cursed sword Muramasa’).
Lore of Yoto Murasama desends on the episode of Tokugawa Ieyasu, the first Shogun on Edo shogunate.
When the grand father of Ieyasu, Hirotada has been killed, the assassin used the Katana forged by Muramasa. And when the father of Ieyasu, Nobuyasu was ordered to Seppuku, the sword used for Kaishaku was also Muramasa.
Ieyasu himself has injured on battle of Sekigahara by Muramasa Yari. Ieyasu feared Muramasa so Tokugawa Shogunate has prohibited for holding Muramasa.
So many Daimyo removed the signature of Muramasa from Nakago like this Tanto.
But some Daimyo Opponents to Tokugawa Syogunate rather collected Muramasa secretly.
The students of the Muramasa are Masashige, Masazane and so on.
I think The Hamon of the Muramasa is very big different from other swordsmiths.
Generally Hamon of Muramasa are square shape Gunome-midare symmetry on both sides of the blade. This is typical characteristics of Sengo school.

1 : Hamon are same shape on both sides of the blade.
2 : Blade is Mitsumune style.
3 : Mekugiana is larger than Tanto forged by any other swordsmiths.
4 : Please take a look to Nakago shape carefully. This Tanago-Hara style is characteristic of Muramasa Tanto.

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Appraisal Quiz #405 (September 16th, 2016)
Who made this sword do you think ?
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Hints. ※The picture will be enlarged

Blade length : 69.2 cm or 27.2 inches.
Sori : 1.3 cm or 0.51 inches.
Mekugi : 1
Width at the hamachi : 3.18 cm or 1.25 inches.
Width at the Kissaki : 2.20 cm or 0.87 inches.
Kasane : 0.63 cm or 0.25 inches.

Shape : The blade is wide and thick with suitable curve and long Kissaki good looking shape.
Jigane : Itame hada well grained with Jinie attach, Chikei work very strong on texture.
Shinogi-ji : Jigane is almost same as Ji and Masame-hada mixed.
Hamon : Niedeki Gunome-midare and double Hamon mixed. Sunagashi nad Kinsuji work very active in Hamon.
Boshi turns back Midarekomi style with Ashi and Sunagashi work.

The clues.

1 : Kesho-Yasuri can't be seen on Kurijiri style Nakago
2 : Wide blade with shallow curve with OoKissaki.
3 : Ths swordsmith who forged this blade is also very skilled for carving.
(This blade doesn't have any Horimono though)

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