Previous answer is
Signature: Nagasone Okisato Nyudo Kotetsu
長曽祢興里入道乕徹

Features:This is a katana by Nagasone Kotetsu, who is rated as Saijyo Saku and also classified as a Saijyo Oowazamono (supreme sharpness). Nagasone Kotetsu was originally an armor maker from Echizen and is said to have moved to Edo around 1656, at the age of 50, where he transitioned to becoming a swordsmith and adopted the name Sannojō.

=====================================
Appraisal Quiz #855 (July 12th, 2025)
Who made this sword do you think ?
=====================================

Blade Length: 2 shaku 4 sun 8 bu 5 rin – 75.3 cm (29.65 in)
Curvature: 6 bu – 1.8 cm (0.71 in)
Mekugi Hole: 1
Width at Base (Motohaba): 3.12 cm (1.23 in)
Width at Tip (Sakihaba): 2.36 cm (0.93 in)
Thickness of rim (Kasane): 0.61 cm (0.24 in)
Sword Weight: 880 grams
Shape: A wide-bladed sword with little taper between base and tip.
It has a strong thickness and deep curvature with a slightly forward curve and an extended medium kissaki.
Jigane: Itame hada, on the ura side partially flowing and collapsing strongly with visible hada, well-forged with ji-nie and embedded chikei.
Hamon: A mixture of gentle waves, gunome, small gunome, and pointed elements with ashi and yo.
There are spots with yubashiri, tobiyaki, and sunagashi.
Boshi: On the omote it turns in a gentle wave; on the ura, it forms a midarekomi.
The tip turns back in a slight hakiwake and ends in a pointed form.

=====================================

Answer will be posted at next Appraisal Quiz.

=====================================