Nobuie is an Owari Province tsubako active from the late Muromachi through the Momoyama period, celebrated alongside Kaneie of Kyoto-Fushimi as one of the "twin peaks" (soheki) of iron tsuba. He is associated with the Kofujita school. Where Kaneie pioneered the pictorial (e-fu) style and favored relatively thin plates, Nobuie's tsuba are generally thicker, possessing what the NBTHK repeatedly characterizes as "a strong sense of mass." His preferred forms are mokko-gata and maru-gata, with rarer variants including kemari-gata and the shodeigata type in which the lower edge flares outward. His signatures are almost always two-character mei, broadly divisible into two types: the hanare-mei ("spaced" or "detached" signature) and the futoji-mei ("bold-character" signature), each associated with distinct stylistic tendencies within his oeuvre.
The defining technical characteristic of Nobuie tsuba, affirmed across every NBTHK evaluation, is "the peerless quality of the forged iron": the surface texture yields "abundant visual effects" and the jihada presents rich "scenery" (jimon no keshiki). His plates are finished in tsuchime-ji (hammered ground), and the iron is worked to achieve a deep, weighty rust patina described as possessing "an elegant taste." Decorative repertoire includes kebori (hairline engraving) of floral motifs, scrolling karakusa, and kikkomon patterns, as well as sukidashi-bori (pushed-up relief) and occasional ji-sukashi (openwork through the plate). Among his most distinctive features are inscribed divine titles such as "Hachiman Daibosatsu" and the Nichiren invocation "Namu Myoho Renge Kyo," together with doka (didactic verses) expressing the essentials of swordsmanship and the prevailing thought of the Sengoku age. The uchikaeshi-mimi (turned-back rim) is singled out as a hallmark: "regarded as the very essence of Nobuie's art," its vigorous modeling and active tekkotsu (iron bones) serve to tighten the pictorial field and complete each work as a unified sculptural statement. His attention extends beyond surface quality to fully three-dimensional modeling, with the subtle nikudori (shaping of the plate) from rim inward toward the nakago-ana noted as "unique to Nobuie."
The NBTHK consistently positions Nobuie tsuba as "works through which one may most fully appreciate the allure of iron tsuba from the late Muromachi through Momoyama periods[[c:1]]." Evaluators praise a quality that transcends technical mastery: the iron is not merely well forged but communicates spiritual content, "quietly conveying the detached spiritual composure of the warrior who lived through the Warring States era." Individual pieces are said to evoke "the bearing of an old warrior" and a spirit akin to kenzen ichinyo (the unity of sword and Zen) and mushin (no-mind). The recurring evaluative refrain describes works that are simultaneously "forceful" and "elegant," combining "a powerful dignity" with "a rich antique fragrance." That these tsuba show to best advantage on uchigatana koshirae[[c:2]] -- the practical mounting of the Sengoku battlefield -- underscores the unity of martial function and aesthetic refinement that defines Nobuie's enduring significance within the tradition of Japanese iron tsuba.
