Nobuyoshi is traditionally regarded as a smith who inherited the lineage of the Senjuin school of Yamato Province. Because he resided at Ryumon-sho in Yoshino District -- an area lying on the route from Yoshino through to Uda -- he is commonly known by the appellation Ryumon Nobuyoshi. No dated works by this smith have been encountered, but transmitted records place his period around the Shoo and Bunpo eras of the late period. Sword reference works list names such as Nobuyoshi, Nagayoshi, and Yoshiyuki within this group, but among them Nobuyoshi alone is particularly well known; indeed, when one speaks of "Ryumon," it commonly refers to Nobuyoshi. His reputation is further elevated by the existence of a celebrated designated a National Treasure, transmitted as having been an imperial possession of Emperor Go-Mizunoo.
Broadly speaking, Nobuyoshi's workmanship may be divided into two principal types. One features lively -ba -- mixed with and -- together with prominently standing , revealing a conspicuous character. The other is a calm in which does not appear, with and along the , presenting a subdued workmanship in which Yamato traits are strongly expressed. In the former type, the is deep and adheres well, with and producing a brilliant, flamboyant temper; in the latter, the tends toward tightness with fine , and the characteristically shows or ends in . The forging typically shows with a flowing tendency toward , thickly covered in with frequent . His inscriptional practice likewise divides into two manners: a -like form in which the right-hand element of the character "" is cut in a manner resembling an abbreviated form of the component sei, called Masa-Nobuyoshi; and a more cursive, sosho-like form resembling the character uji, called Uji-Nobuyoshi. In general, blades bearing the former style of signature tend to show a more tightly forged structure, whereas those with the latter often incline toward more standing grain.
Nobuyoshi's work occupies a distinctive place within the as a smith in whom Yamato coloration and temperament coexist -- a duality that the repeatedly identifies as characteristic and by which his attributions are confirmed. His finest pieces are distinguished by both and that are bright and clear, with a particularly superior quality of workmanship described as "among the finest of this smith's extant works." The is consistently noted as bright, the internal activity rich with , uchi-noke, , and finely applied . Works in both modes are praised as -- sound and well-preserved -- and his signed examples, rarely encountered, are regarded as precious. Beyond technical accomplishment, the observes in his best an abundant and robust overall build, qualities that together with "a high sense of dignity and formality" affirm his standing as the preeminent smith of the Ryumon line.