Heianjō Nagayoshi is the Kyoto smith whom the published sources name, again and again, in a single breath with Yoshinori as a representative maker of in the period. He is said to descend from Mitsunaga of Heianjō, a smith of the late , and the swordbooks carry his name back to the ; but the surviving record does not reach that far. No work looks so early, none is dated before the , and the body of his blades falls between the Bunmei and Tenbun eras, the earliest dates clustering around Bunmei and Meiō. One signed carries a Meiō date that the published sources value as documentary material for the name itself. The name is understood as one borne by several smiths across several generations, so that Heianjō Nagayoshi is less a single man than a Kyoto workshop hand carried forward through the late .
What makes that hand recognizable is not one temper but a manner, and its clearest mark is in the . The published sources single out the close correspondence of the on the and the , the temper of one face answering the other, and on this point above all they bind his work to Muramasa of . Of one the commentary says plainly that in workmanship and in the cut of the tang it resembles Muramasa, 「すべて勢州の村正によく似ている」, and infers a deep relationship between the two; of another it finds the matching faces a distinctive feature, 「表裏の刃文が揃うところに特色」, shared with the Sengo line of Muramasa. Over a finely worked Kyoto he sets a small mixed with , entering, the tending tight with , the a . His are often broad for their length and stocky, scarcely curved, a stance the commentary calls one frequently met in his work.
The is the constant beneath the changing temper. It is a or , tightly packed and mixed with flowing , with adhering and at times fine , and over it lies a faint whitish cast, the that places him after the great schools of the capital rather than among them. On his finest the forging tightens into a dense Kyoto and a rises from below the to become a . It is a refined steel, the surface the published sources expect of him, quiet and clean rather than brilliant, the late-Yamashiro against which his more decorative tempers read.
His range across that is unusually broad for one hand, and the published sources lay it out as such. On his and the temper is most often a broad or medium , set over a -toned lower half where small linked form a -like base, with small and a tight, bright ; one shows the canonical division, a with pointed at the base running up into a wide . At the other pole stands his most flamboyant register, an all-over of with pointed and angular elements and a -like form, into which , and enter until the temper covers the whole blade, the turning back long into the with and throughout. The published sources call this temper comparatively uncommon in his work and read it as a private emulation of the Kyoto master Hasebe, 「京の先達長谷部の皆焼に私淑」, noting that, unlike the older , his stays tight, and that the thin and the long together point to the Hasebe model.
What separates Nagayoshi from the company he keeps is exactly what the judges name. From Yoshinori and the ordinary Sue-Yamashiro smiths he is set apart by the matching of his two faces and by the sheer breadth of his hand, the same maker passing from a Muramasa-akin to a quiet to a Hasebe ; from the older he is held apart by the restraint of his . Above all he is known as a carver. The published sources call him an outstanding master of , 「彫物の名手としてもその名が高い」, and his grass-style runs through the great majority of his blades, the dragon's tail cut where it crosses the sword so that the sword appears raised in relief, a manner they hold scarcely confusable with any hand other than his own. The carving is part of the , not an ornament on it.
For the collector he is a Kyoto name of the late , graded Jō-jō by Fujishiro. His designated record runs entirely through the rank, with fifteen blades on record and no National Treasure or Important Cultural Property among them; the value of his name rests instead on the signed, often dated works and on the diversity of his oeuvre, , , and together with the carvings he excelled in. The published commentary calls one of his 「同工屈指の優品」, foremost among the smith's own works, and several of his typical superior examples. Provenance is sparsely recorded for his blades, so the safest thing to say is that signed Heianjō Nagayoshi works are held quietly across private collections rather than concentrated in famous houses. Only a small number fall in the tradeable tiers, so a signed example comes to light from time to time rather than often, and a sound, signed, carved blade by him is a satisfying thing for a collector to encounter, a document of how the Kyoto forges worked on at the close of the age.