Nobufusa is an early smith of the Fukuoka school in , working in the opening decades of the period. The published sources count him among the , the swordsmiths who served Retired Emperor Go-Toba in monthly rotation, and place his activity around the Kenpō era. They are candid about how little survives: reliably signed works are exceedingly few, and the published record names only the at Hie Shrine, the formerly in the Imperial collection now in the Tokyo National Museum, and the Hayashibara beside a small number of others. The enters the name under both , around the Genryaku era, and Fukuoka , around the Kenpō era, and the published sources read the signed survivals as the Fukuoka hand, of the Ko- generation that followed Norimune. His is one of the first hands to carry the manner forward, and the survival of even a handful of signed blades makes him a document of how the school began.
His recognized work is a slender of high , made and kept , the width narrowing toward a with the upper half inclining gently forward, an elegant shape the published sources read as the period's own. The hand itself is the tell. Over the he sets a -toned temper, calm rather than flamboyant, into which , and small are mixed, with and entering well, the -dominant and carrying only a little , at times subdued. This is the quiet, archaic register the published sources hold apart from the showy of the mid- school, and on one they appraise the and together and conclude the blade is "to be judged the work of a smith of the Ko- lineage". The runs straight to a small round, on one finishing in a .
The is the constant beneath that quiet temper. It is an , well forged and at times mixing , packing into a dense where the forging tightens, with and and an that stands clearly on every example. On the the reflection comes as a , rising from dark patches in the steel, which the published sources say demonstrates the height of his forging technique; on the Kujō-family pair it stands as a . This is the old- he shares with the school, but the brightness of the reflection and the gathering of small on his edge set him apart from the plainer smiths around him. The activity is carried in the and rather than in towering clusters, the whole reading archaic and graceful rather than ornamental.
Within the signed work the published sources draw a careful internal distinction. The body of it is the -toned just described, but the pair of Important Art Objects long held in the Kujō family open into something fuller: there the temper begins from a at the base and proceeds as a , and entering abundantly, one of the two worked in with and . The published sources hold the two by the hand and call it one of their highlights that "the rises at the boundary". The remaining face of his record is the whose original signature was preserved as a ; there the becomes a packed with the standing, the base mixing with abundant internal activity, and the published sources prize it as a scarce signed example, accompanied by a Kōchū of Kyōhō 1, in which "the archaic virtues of early are well displayed in the and ".
What separates the early Nobufusa from his neighbours is exactly what the judges name. He stands at the threshold of the school, before its great flowering into the flamboyant of the mid- Fukuoka, Yoshioka and Katayama hands; his temper is read instead in the older, calmer key, the bright with and the edge gathering only small . The published sources also record the old dispute over whether the smith writing 延房 is the as the one signing 信房, and follow the view, dominant today, that they are separate individuals of the early Fukuoka group. On the they note that the signature closely resembles that of the Kujō-family Important Art Object, a kinship of that makes the blade, in their words, "a sword of high documentary value".
For the collector he is a rare early name rather than a market presence. Fujishiro grades him Jō-jō , and the Tōkō Taikan places his work high among hands. He has no National Treasures and no Important Cultural Properties of his own on record; his surviving designated work runs instead through the and tiers and the prewar Jūyō Bijutsuhin, only a few designated blades in all, and the is one the published sources call "among the foremost works by the smith". His blades are preserved in institutions and long-held collections grounded in their own provenance: the Tokyo National Museum and the Hayashibara Museum of Art hold by him, the Okayama Museum of Art Foundation another, and the recorded provenance runs through the Kujō family, the Kishū Tokugawa, the Ōmura house, and the Shōwa collector Kazama Yōkichi. With so few signed pieces in existence and most held rather than traded, a signed Nobufusa comes to light only rarely; a privately held example is among the more notable things an early- collector could hope to encounter.