The dated work of Osafune Motoshige opens with a tantō inscribed Shōwa 5 (1316) and closes in the Jōji era of the mid Nanbokuchō period, a span of some fifty years. Across this interval the published sources allow a first and a second generation, while noting that no settled consensus exists as to where the boundary falls. On one point the record is constant: Motoshige of the Osafune group in Bizen was a smith of a line distinct from Kanemitsu and Chōgi. The old genealogies derive the line instead from Hatakeda Moriie: the son of the second-generation Moriie was Morishige, and Morishige's son was Motoshige. He stands apart both from the Osafune mainline of Mitsutada and Nagamitsu and from the houses beside him, and the individuality of his blades answers to that separate descent.
The manner the published sources assign him returns almost word for word. The forging mixes flowing masame and jifu; in the hamon, angular gunome stand out over a suguha tone, and the whole slants in saka-gakari; within the temper work saka-ashi and yō; the bōshi becomes pointed. The notes conclude that "the viewing points of this smith and his school lie precisely in the point where the Aoe temperament is mixed in"[[c:1]]. The squared teeth are the most personal of these marks: the sources describe "angular gunome with the yakigashira aligned in a straight line, peculiar to this smith"[[c:2]], read most clearly around the monouchi. The nioiguchi tends toward tightness with ko-nie, and fine kinsuji and sunagashi thread the ha.
The jigane is an itame mixed with mokume and flowing grain, standing somewhat across the surface. Very fine ji-nie attaches, fine chikei enter, jifu is interlaced, and a midare-utsuri rises, often vividly. Of one unsigned katana the sources name the slanting hamon and this mokume-laced, standing forging surface, "what is termed the cicada wing"[[c:3]], as the conditions that point an appraisal to Motoshige. His uchi-zori tantō are forged in ko-itame with a slight flowing tendency, and the refined forging of his best tachi appears at a glance almost a pure ko-itame.
The record divides into clear registers. At its head stands the group called Ko-Motoshige: two-character signatures cut with a thick chisel on the haki-ura above ō-sujikai file marks, with a Jūyō Bijutsuhin tachi dated Kagen 2 (1304). Of one such slender tachi with koshi-zori the sources write that the suguha-toned ha with chōji and ko-midare, over an itame carrying jifu, is a workmanship "Aoe-like through and through"[[c:4]]. They hold this hand to be a different and somewhat earlier man than the long-signature Osafune Motoshige, leaving open whether he was the ancestor of the line or a smith connected with Aoe. The dated Kamakura work runs from Shōwa 5 through Karyaku into Kenmu: tantō of standard proportions with uchi-zori, in kataochi-gunome so close to the older manner that one dated blade reads "almost as though one were viewing the work of Kagemitsu"[[c:5]]. From the Nanbokuchō years the build turns grand: wide mihaba with little taper, shallow sori, a large kissaki, the Enbun and Jōji stance. The bulk of what survives answers to it as ō-suriage unsigned katana; among the signed pieces stands an ubu tachi of 94.45 cm preserving the full form of the period. Edo tradition counted Motoshige among the three sages of Sadamune (貞宗三哲) beside Nobukuni and Hōjōji Kunimitsu, a claim the published sources find "hard to credit out of hand"[[c:6]]: most of his surviving work is plainly Bizen, with fewer Sōshū-tinged pieces than Kanemitsu or Chōgi. The exception is real: in the wakizashi transmitted in the Shimazu family, an Important Cultural Property, the nie of ji and ha grows extraordinarily strong and chikei and kinsuji stand out.
A blade of his may show "at a rough glance a manner that could be taken for Aoe"[[c:7]]; yet the angular teeth aligned at the yakigashira and the vividly standing midare-utsuri return the appraisal to Motoshige, a Bizen temperament at base that wears the air of neighboring Bitchū. Against Kagemitsu, to whom the old books liken him, the wider ha, the pointed bōshi and the loosened flowing masame and jifu in the jigane reveal "the individuality of a Motoshige whose line differs from that of Kagemitsu and his kind"[[c:8]]. The same viewing points are shared, the notes add, by his school, Shigezane and the rest, who carried the squared, slanting manner through the Nanbokuchō period.
He is rated Jō-jō saku in Fujishiro's grading, and 159 designated works stand on record: seven Important Cultural Properties, nine Jūyō Bijutsuhin, and 142 blades across the Tokubetsu Jūyō and Jūyō tiers, twenty-one of them Tokubetsu Jūyō. Unsigned blades outnumber signed ones, ninety-nine against fifty-six, so he is met most often as an ō-suriage unsigned katana. The named pieces carry the history: the Kenmu 1 (1334) tachi called "the white eyebrow among his works"[[c:9]]; the Kan'ō 3 (1352) tachi of Kan'in-no-miya transmission; the Satake katana bestowed by Shōgun Tokugawa Ienobu in Hōei 8 (1711), whose Hon'ami Kōon gold-inlay attribution the sources call "entirely just"[[c:10]]; and the Date family katana that may be the very Motoshige the Tokugawa Jikki (徳川実紀) records Iemitsu granting Date Masamune in Kan'ei 1 (1624). Twenty-nine blades carry recorded provenance, through the Date, Satake, Uesugi, Hachisuka, Hosokawa, Shimazu, Owari Tokugawa and Yanagisawa houses and into the Imperial Family. The Important Cultural Properties can never trade, and holdings of the Tokyo National Museum, the Sano Art Museum, the Hayashibara Museum of Art, the Seikadō Bunko Art Museum, Uesugi Jinja and the British Museum stand outside the market. Yet with 142 blades in those tiers he remains among the few major names of Nanbokuchō Bizen a collector can still realistically hold, and the hand declares itself wherever the squared, slanting ha runs beneath a vivid utsuri.
