Nobuie of Owari is named in the published sources, together with Kaneie of Fushimi in Kyoto, as one of the twin pinnacles of the iron , and his designated record of fifty-six guards is built almost wholly on forged iron. The commentary places his production chiefly in the Sengoku period, from the end of into . Who he was is less certain than what he made. The common account makes him the seventeenth generation of the Myochin armourers, who took the character from Takeda Shingen, and another tradition has him leave Owari for at Shingen's invitation; the published sources report both as tradition and call the move unproven. They also state that the name was not one man's. Several smiths signed Nobuie at nearly the same time at the end of , others did so in the period, and they probably lived in several provinces beginning with Owari. Armourer's helmets signed Nobuie, some dated in the Tenbun era, survive, but neither their signatures nor their match those on the , and forgeries made since the period have further clouded the study. One guard in the record is described as the work of the first-generation Owari maker, signed in the so-called left-leaning hand.
His merit is stated in a sentence the published sources repeat, in close variants, in forty-five of the sixty records: the forging of the iron is without equal, the surface pattern of the plate (jimon) is rich in scenery and elegance, and the guard shows to best advantage on an mounting. Set against Kaneie, whom they credit with founding the pictorial on thin plates, Nobuie's guards are thick and carry a sense of mass. The plate is most often a hammered , its hammer marks described as alive and moving, and the working of the iron throws up iron bones () at the rim and across the flat. The patina is deep and heavy, at times purple with a reddish cast, and one record calls this beautiful rust "the very life of the Nobuie ." Of a plain guard with water-drop openwork the commentary writes that "few make known how strong and beautiful iron can be." Of a tortoise-shell guard with Amida file marks, the piece the late Akiyama Kyusaku treasured above all his others, it speaks of "the skill of no skill."
His shapes are mostly and round, rarely the kemari form or the aori form whose lower edge flares, and the published sources note that plate guards far outnumber openwork. The modelling is low at the centre and high toward the rim, and the rim is hammered tight and turned back as an , often with a small raised edge. One record calls this lively turned-back rim "what is called the true essence of Nobuie," and another finds the curve running from rim to peculiar to him, the sign of a maker who attended to the whole three-dimensional form and not only to the iron. On this plate he cuts , the hairline engraving he favoured: gourds, morning glory and arrowhead, tortoise-shell and broken tortoise-shell, pine needles and seaweed, arabesque of paulownia and ivy, plum, maple and the horned owl in a tree. Chrysanthemum stamps scattered across the surface, which the commentary associates with the hanare signature, add to the pattern of the plate. relief and small openwork appear more rarely, and a guard of cherry blossom and water wheel inlaid in brass is called "an extremely rare technique among Nobuie ."
The inscribed guard forms a second register, which the published sources name a major point of interest in his work: the divine name , the daimoku Namu Myoho Kyo, and verses on the secrets of the sword and the thought of the age, all cut in . One guard sets the daimoku on the front and the five-element characters on the back; another carries the proverb of the old man of the frontier and his horse; a third shows three skulls in relief on the front and a seven-character daimoku on the back. Of the guard bearing the Yumiya Hachiman verse, the commentary writes that "the composure of the warrior who lived through the Warring States comes through, quiet and grave." His signature is almost always the two characters Nobuie. Many character forms are accepted, but they divide broadly into the and the futoji-; Akiyama Kyusaku sorted them into seven types, among them a , after Nakamura Kakudayu had compiled his Nobuie -shu at the end of the period. Only one guard in the record carries a beside the name.
The wheel openwork (kuruma-) places him among his Owari contemporaries, for the published sources find the same design in the work of Hoan, Yamayoshi and Kanayama. His own examples, with fourteen or sixteen spokes, stand apart for their heavy outer ring and the uneven run of the spokes, and the fourteen-spoke guard is called among the finest of his works. The commentary also records why warriors favoured him: a Nobuie guard suited a mounting of any taste and was valued for that harmony and for its strength. The repeated judgment is that these are the works in which "the appeal of the iron from the end of through can be savoured to the full."
For the collector, Nobuie's record is fifty-six guards designated , four of them raised to ; he has no National Treasures and no Important Cultural Properties. Provenance is recorded for only a few: a daimoku guard handed down in the ducal Date family, the tortoise-shell guard from the collection of Akiyama Kyusaku, and the fourteen-spoke wheel guard, which Nakamura's book records passing from Hamada Motohichi of Osaka to Tsunaya and which was kept in the Furukawa family. No current holder is recorded against his name. Among makers his designated guards are relatively numerous, and one may come forward from time to time; a signed plate of fine hammered iron with a lively turned-back rim, in either signature class, shows the side of his art the published sources praise most.
