One tachi by Yasuhiro carries the date Tokuji 2 (1307), 10th month, and signs in full 'Bizen no Kuni Osafune-jū Ukon Shōgen Yasuhiro saku'[[c:1]], fixing him to the late Kamakura years at Osafune. 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 Osafune 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 Jūyō 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 Osafune 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 Osafune of his generation builds a flamboyant chōji and gunome midare, Yasuhiro tempers on a suguha base across the whole of his surviving body. The representative long tachi takes a suguha at the monouchi with small ashi, opening below into a suguha-based temper mixed with small gunome and small chōji, with small ashi and yō entering and small nie 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 gunome, small chōji and occasional gunome read as activity inside a suguha rather than as a midare in its own right. Against the choji-heavy mainstream this suguha keynote, taken together with his off-line signature, is the feature a collector reads first.

Over an itame jigane with ji-nie he raises the Bizen reflection that places him securely in his school. On the representative tachi a midare-utsuri stands distinct and clear; on a shortened katana it appears only faintly, and in the monouchi on the sashi-omote it takes on a stepped dan-utsuri aspect, the variegated reflection of late-Kamakura Osafune steel. The bōshi runs straight throughout, turning back in a shallow ko-maru. The forging itself divides his work into two hands. On his most controlled blades the steel tightens to a well-worked ko-itame with chikei entering and the nioiguchi drawn tight and clear, and the published sources judge this register close in ji and ha to the contemporary orthodox Osafune, well-fleshed in niku and sound. On his more individual blades the itame is mixed with mokume and stands somewhat, flowing toward masame, the habuchi roughened in places, with kinsuji and sunagashi active across the temper; of one such tachi the sources write that compared with the contemporary orthodox main line the ji and ha 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 ko-itame and the clear, controlled suguha that the published sources set beside the orthodox work without finding it short; the representative tachi belongs here, judged sound in construction and in both jihada and hamon, a piece they call one that 'does not fall short even when compared with the orthodox Osafune main line, a representative superior work by Yasuhiro.' At the other pole stands the rustic hand, the standing masame-leaning itame with its kinsuji and sunagashi, 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 tachi, and the bare two-character mei, while two of the blades are shortened and carry their original signature folded over as an orikaeshi-mei, 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 suguha base with its small gunome and small chōji, the midare-utsuri shading toward dan-utsuri over an itame jigane, the ko-maru bōshi, and on his individual pieces the rustic masame-leaning forging with kinsuji and sunagashi are the marks that set him apart from the chōji-dominant Osafune mainstream. The published record is candid about where this places him. On the Tokuji 2 tachi 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-Kamakura Osafune 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 tachi is accompanied by a Hon'ami Kōchū origami of the Kyōhō era assigning it a valuation of one thousand kan, and the prewar Important Art Object certifications record owners in Tanaka Taisuke of Osaka and Hon'ami 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 tachi prized first as evidence of so rare and so exactly dated a hand, and the shortened katana 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-Kamakura Osafune hands, a documentary landmark when one does appear.

One tachi by Yasuhiro carries the date Tokuji 2 (1307), 10th month, and signs in full 'Bizen no Kuni Osafune-jū Ukon Shōgen Yasuhiro saku'[[c:1]], fixing him to the late Kamakura years at Osafune. 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 Osafune 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 Jūyō 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 Osafune 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 Osafune of his generation builds a flamboyant chōji and gunome midare, Yasuhiro tempers on a suguha base across the whole of his surviving body. The representative long tachi takes a suguha at the monouchi with small ashi, opening below into a suguha-based temper mixed with small gunome and small chōji, with small ashi and yō entering and small nie 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 gunome, small chōji and occasional gunome read as activity inside a suguha rather than as a midare in its own right. Against the choji-heavy mainstream this suguha keynote, taken together with his off-line signature, is the feature a collector reads first.

Over an itame jigane with ji-nie he raises the Bizen reflection that places him securely in his school. On the representative tachi a midare-utsuri stands distinct and clear; on a shortened katana it appears only faintly, and in the monouchi on the sashi-omote it takes on a stepped dan-utsuri aspect, the variegated reflection of late-Kamakura Osafune steel. The bōshi runs straight throughout, turning back in a shallow ko-maru. The forging itself divides his work into two hands. On his most controlled blades the steel tightens to a well-worked ko-itame with chikei entering and the nioiguchi drawn tight and clear, and the published sources judge this register close in ji and ha to the contemporary orthodox Osafune, well-fleshed in niku and sound. On his more individual blades the itame is mixed with mokume and stands somewhat, flowing toward masame, the habuchi roughened in places, with kinsuji and sunagashi active across the temper; of one such tachi the sources write that compared with the contemporary orthodox main line the ji and ha 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 ko-itame and the clear, controlled suguha that the published sources set beside the orthodox work without finding it short; the representative tachi belongs here, judged sound in construction and in both jihada and hamon, a piece they call one that 'does not fall short even when compared with the orthodox Osafune main line, a representative superior work by Yasuhiro.' At the other pole stands the rustic hand, the standing masame-leaning itame with its kinsuji and sunagashi, 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 tachi, and the bare two-character mei, while two of the blades are shortened and carry their original signature folded over as an orikaeshi-mei, 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 suguha base with its small gunome and small chōji, the midare-utsuri shading toward dan-utsuri over an itame jigane, the ko-maru bōshi, and on his individual pieces the rustic masame-leaning forging with kinsuji and sunagashi are the marks that set him apart from the chōji-dominant Osafune mainstream. The published record is candid about where this places him. On the Tokuji 2 tachi 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-Kamakura Osafune 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 tachi is accompanied by a Hon'ami Kōchū origami of the Kyōhō era assigning it a valuation of one thousand kan, and the prewar Important Art Object certifications record owners in Tanaka Taisuke of Osaka and Hon'ami 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 tachi prized first as evidence of so rare and so exactly dated a hand, and the shortened katana 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-Kamakura Osafune hands, a documentary landmark when one does appear.