Nobufusa (延房) was an early smith of the Fukuoka Ichimonji lineage in Bizen Province, and is counted among the ban-kaji--the appointed attendant smiths who served Retired Emperor Go-Toba. Sword reference works place his period of activity around the Kenpo era (1213-1219). There has been a theory identifying the smith signing 延房 as the same person as the Nobufusa who signed 信房; however, the prevailing view today regards them as separate individuals. Authenticated extant works that are reliably signed are "exceedingly few"; apart from the tachi at Hie Shrine (Important Cultural Property), the tachi in the Tokyo National Museum, and the tachi in the Hayashibara Museum of Art, only a small number of signed examples are known.

The sugata of Nobufusa's tachi embodies the elegant archaic ideal: slender with a pronounced koshizori, evident funbari, and ko-kissaki, presenting a form that "clearly displays period characteristics." His kitae is itame-hada mixed with mokume, overall well-forged, with ji-nie and fine chikei; a midare-utsuri or mottled jifu-utsuri stands out, and the forging in his finest examples achieves a dense, tightly packed (tsumi-gokoro) texture. The hamon is fundamentally suguha-based--a chu-suguha tone mixed with ko-choji, ko-midare, and ko-gunome--with plentifully entering ashi and yo and well-adhering ko-nie. The NBTHK observes that both ji and ha "clearly present the archaic aesthetic virtues characteristic of early Ichimonji work."

The setsumei consistently describe Nobufusa's work as imbued with an "archaic grace" and "refined, high-class style." Several blades retain their original ubu nakago, and the rarity of signed examples gives each authenticated work heightened documentary value. One tachi bears a mei closely resembling that of a Juyo-Bijutsuhin blade formerly in the Kujo family, while another carries a Hon'ami Kochu origami from Kyoho 1 (1716). Two works designated as Important Art Objects were formerly transmitted within the Kujo and Izumo Senke families respectively, underscoring the esteem in which this early Kamakura master has been held across centuries of connoisseurship.