Nobunaga is transmitted as a smith of the group of Yamato Province who, in the early period, relocated to Asako in . Smiths using the name continued for several generations, and these are collectively referred to as "Asako ." Their workmanship resembles that of the Fujishima group, and their period of activity is said to have centered around the Oei era (1394-1428), with the line continuing into the late period.
In terms of forging, Nobunaga's works display mixed with and , with the grain standing out and showing a somewhat darkened tone characteristic of Hokuriku workmanship alongside a Yamato temperament. The most commonly takes the form of an angular -- the hallmark of this smith -- though works in and are also encountered. and enter, adheres well, and and appear. The is often executed in . Among the more remarkable surviving pieces, a displays two distinct modes of workmanship on its opposing faces: on the a based on mixed with "boxed" elements, and on the reverse a shallow , demonstrating Nobunaga's capacity for vigorous, open-handed work rich in along the .
Signed works by Nobunaga are rare and highly valued as documentary material. Among his well-known works is one formerly owned by Hosokawa Sansai. His , though typically found in condition, clearly display the period character of the early era and are of good quality. The range of his extant work -- from angular pieces exhibiting the full force of the -Fujishima idiom to refined in condition -- attests to a smith of considerable versatility whose output carries high documentary value for understanding both the Asako lineage and the broader dissemination of Yamato tradition into the Hokuriku region.