This is a very good sunnobi tanto with mounting from Kyushu made at the very, very end of the Koto period on consignment. The flawless blade is an ubu, unaltered 1-hole zaimei Koto signed "Dotanuki Kiyokuni", hira-zukuri with a slight sori; tang ends in a squarish kuri-jiri and is clearly signed, with appropriate age. Blade is polished. Very clear, tight itame-nagare with prominent minute chikei everywhere was produced by mixing steels. Combined with a very active and irregular hamon of mainly gunome-midare including floating islands of temper in parts of the ji and even some muneyaki, the imozuru or "potato vine" type of dark kinsuji wiggling randomly through the hamon indicate uniquely Satsuma work. The Dotanuki group emerged in the Momoyama Period as descendants of the Enju smiths, serving Hideyoshi and, more specifically, Kato Kiyomasa. One source suggests that Kiyokuni and others got use of the "Kiyo" in their name from servitude to Kiyomasa. Kiyokuni is also said to have eventually resided and made swords in neighboring Satsuma; this blade seems to confirm such information. The Dotanuki group is another name associated with extraordinarily keen swords. This blade came with a mounting in need of restoration; hamidashi-type matching copper tsuba, fuchi, koiguchi, and kojiri scrolled with vines and mon. Black lacquer ishime saya needs repair and is missing the kogai strip and kurikata. Solid string wrapped handle is missing one tomoe menuki and the kashira; the kashira can be replaced with black horn. The whole mount is very restorable. Blade comes in shirasaya with old copper habaki.