Among the five extant blades carrying Tomoyuki's attribution, only one is signed in full: a cut with the large four-character Tomoyuki, which the published sources call an exceptionally valuable example as documentary material precisely because signed work by this smith is so scarce. Tomoyuki was a swordsmith of the Yamato school active in the period, the school being the contingent of smiths attached to -dera in Yamato whose founder was Kuniyuki and which flourished from the late period through the era and on into the . One tradition holds that Tomoyuki was a grandson of Kuniyuki. The school's antiquity is fixed by the dated of Aritoshi, transmitted as being of this lineage, which bears an inscription of Einin 6 (1298), so that the production of the line is understood to reach back earlier still. What the record makes plain about Tomoyuki himself is the rarity of his hand: the published sources state outright that his signed works are exceedingly rare, and that most of the school survives as unsigned pieces fixed by appraisal.
His is the manner, and the most constant feature across the whole of his surviving work is the , which runs straight and is then swept with , most often ending in without a turnback. The phrase the published sources use of his , that the point is brushed and finishes in , recurs in one form or another on every blade in the corpus, from the to the great to the dated . Over a quiet line he builds his temper: a base waved only shallowly into notare, into which enter , small , and , with unravelling along the . The activity within the is the part the judges single out. Even among works given to the school, they write, the working of and inside the tempered area is conspicuous, the thick and brightly clear, with and flashing through it repeatedly. It is in that abundant glittering , on the signed , that the published sources say one may perceive Tomoyuki's capability.
The is the Yamato tell. He forges an that flows, gathering near the edge into , so that the steel stands somewhat open, with thick laid over it and entering the grain. On the dated the forging tightens into a well-knit with fine throughout, the phrase the appraisers set down as well-forged. On his finest the carries a tendency to stand open and raises a , the reflection that on this smith is a product of rather than of the , and it is there, the published sources judge, that the characteristics of the school are most strongly manifest in both and . The temper on that blade is a mixed with small and small , the edge breaking into , and , the bright and clear.
The surviving corpus divides by construction rather than by period, and the division is itself a fact about how he comes down to us. The are wide-bodied blades cut down to , their attribution argued from the markedly elongated and from the activity at its strongest, for the texts are candid that on a shortened blade no individuality singling out Tomoyuki can be discerned, even while there is no disagreement that it is a masterpiece of the school from the . Against these stand the few signed pieces that anchor him. The is a wide with , carrying a on the and a shōbu- on the . The is a ryō- blade dated Shōchū 1 (1324), with a two-character signature on the and the date on the , and the published sources frame it within a standing scholarly problem: signed Yamato are few, and the texts can cite only a Shigeyoshi Nyūdō of Genkō 4, a Norizane of Shikkake, a Kanetoshi of and a small number of others, concluding that the study of Yamato remains to be awaited.
The lineage question is left expressly open, and the candour of the record on this point is itself characteristic of how thin the documentary base is. The name Tomoyuki, the published sources note, appears in the sword-signature reference works among the Yamato Senjuin group as well as within the line, and one early entry adds that there is also a work of his bearing a Bunwa-era date. On the dated the judges allow that the piece is Yamato beyond doubt, yet observe that a tends to thin out the distinctive traits of a particular lineage, and so reserve the precise descent for future study. His distinction is best drawn not by contrast with the other Yamato schools but by his own grounded traits: the flowing -leaning , the -based brushed into a , and the conspicuous and within a bright, -laden edge are the marks the appraisers read as and, on the elongated , as Tomoyuki in particular.
The whole of Tomoyuki's recorded output stands at the highest civilian level of designation, five blades among the Important Sword tier and none higher, with no National Treasure or Important Cultural Property among them. There is no recorded provenance through the houses to draw upon, and no institutional holder is named in the published record, which is consistent with a smith known almost entirely through unsigned attributions and a handful of signed survivals. What a collector might realistically encounter is therefore confined to that small designated body, the and cut down from the school's grander blades, the signed prized first as documentary evidence, and the dated with its gold- cloud-and-dragon sankō-zuka mounting. Such pieces are held far more often than traded, and a signed example in particular, valued as it is for fixing so rare a hand, comes to the open market seldom and stands as a landmark of Yamato work when it does.
