One by Yasuhiro carries the date Tokuji 2 (1307), 10th month, and signs in full ' no -jū Ukon Shōgen Yasuhiro ', fixing him to the late years at . The published sources place him there working at almost the same time as Kagemitsu, with dated pieces surviving from the Shōan and Tokuji eras, and they are careful to add that he styled himself Ukon-no-shōgen and Sahyōe-no-jō. Few of his works remain. The point the published record returns to on every blade is that although he lived at his manner of signing differs from the orthodox main line of Nagamitsu, Kagemitsu and Chikakage, a difference that the sources read as one of lineage rather than of period; one commentary states it plainly, that the way he signs 'differs from that of Kagemitsu and also from Chikakage, suggesting a difference in lineage from the main line.' He is thus a contemporary of the great names who stands a little apart from them, and his blades are weighed against their work as the measure of his standing.
The keynote that separates Yasuhiro from those names is the temper itself. Where the orthodox of his generation builds a flamboyant and , Yasuhiro tempers on a base across the whole of his surviving body. The representative long takes a at the with small , opening below into a -based temper mixed with small and small , with small and entering and small adhering. The same calm hand recurs from blade to blade, the disorder always worked within the straight line rather than displacing it, so that the small , small and occasional read as activity inside a rather than as a in its own right. Against the -heavy mainstream this keynote, taken together with his off-line signature, is the feature a collector reads first.
Over an with he raises the reflection that places him securely in his school. On the representative a stands distinct and clear; on a shortened it appears only faintly, and in the on the it takes on a stepped aspect, the variegated reflection of late- steel. The runs straight throughout, turning back in a shallow . The forging itself divides his work into two hands. On his most controlled blades the steel tightens to a well-worked with entering and the drawn tight and clear, and the published sources judge this register close in and to the contemporary orthodox , well-fleshed in and sound. On his more individual blades the is mixed with and stands somewhat, flowing toward , the roughened in places, with and active across the temper; of one such the sources write that compared with the contemporary orthodox main line the and show 'a somewhat more rustic character, noteworthy as an example that demonstrates one facet of Yasuhiro's individual style.'
The small corpus is therefore best read along that two-pole axis rather than by period. At one pole stands the refined hand, the tight and the clear, controlled that the published sources set beside the orthodox work without finding it short; the representative belongs here, judged sound in construction and in both and , a piece they call one that 'does not fall short even when compared with the orthodox main line, a representative superior work by Yasuhiro.' At the other pole stands the rustic hand, the standing -leaning with its and , the manner the sources name his own individual style. Orthogonal to both runs the signature, the feature that fixes the attribution and the lineage at once: the corpus divides between the full long signature with title and date, as on the Tokuji 2 , and the bare two-character , while two of the blades are shortened and carry their original signature folded over as an , on one of them the lower character now indistinct.
His distinction is drawn most surely from his own attested traits, not from the mainline by contrast. The base with its small and small , the shading toward over an , the , and on his individual pieces the rustic -leaning forging with and are the marks that set him apart from the -dominant mainstream. The published record is candid about where this places him. On the Tokuji 2 the appraiser Honma noted that his technical level is reckoned below Kagemitsu and Chikakage, and that the blade was accepted for designation on account of its rarity, adding that the Tokuji 2 date is itself of great documentary value. No successor line is drawn from him; the surviving body is too small and his lineage too peripheral for the record to carry the school forward through his hand, and he is read as a discrete late- smith whose value lies in his position beside the main line.
The whole of Yasuhiro's record stands at the level of designation a private collector can realistically meet, three blades among the Important Sword tier and two among the prewar Important Art Objects, with no National Treasure and no Important Cultural Property among them, and the connoisseurship of his name rests on documentary value as much as on artistry. Provenance is thin but real. The representative is accompanied by a Kōchū of the Kyōhō era assigning it a valuation of one thousand , and the prewar Important Art Object certifications record owners in Tanaka Taisuke of Osaka and Sumio of Tokyo. No institutional holder is named in the published record of his blades, which is consistent with a smith known through a handful of designated survivals rather than through famous collections. What such a collector might encounter is confined to that small designated body, the long signed prized first as evidence of so rare and so exactly dated a hand, and the shortened carrying its folded signature. Pieces of this kind are held far more often than traded, and a signed Yasuhiro, dated and off the orthodox line, is among the less frequently met of the late- hands, a documentary landmark when one does appear.