Yoshitsugu is identified as the first generation of the Naka-Aoe school, one of the representative smiths of the Aoe group in Bitchu Province during the late Kamakura period. His full signature reads "Bitchu no Kuni Aoe-ju Uemon no Jo Taira Yoshitsugu saku," and he is known to have frequently cut long inscriptions accompanied by date markings. Dated works survive from the Gentoku (1329--1331), Karyaku (1326--1329), and Kenmu (1334--1338) eras, establishing his active period with unusual documentary precision. Among his most notable pieces are a tachi in the Tokyo National Museum designated as an Important Cultural Property and another Important Cultural Property at Hie Shrine, the former bearing a tachi-mei and the latter a katana-mei.

Yoshitsugu's forging characteristically shows a tight ko-itame mixed with ko-mokume, forming a dense, standing texture with fine ji-nie and delicate chikei; jifu are intermingled, and a deep kanairo tone pervades the clear steel, occasionally with sumi-hada and a tendency toward nagare-gokoro. His hamon is fundamentally suguha-based, mixed with small midare and, in certain works, a hint of gunome-choji; the temper is laid with nioi and deeply adhering ko-nie, with ashi and yo entering abundantly. In the upper portions of certain blades, yubashiri and tobiyaki appear, giving rise to a nijuba-like tendency, while above the monouchi the temper may become choji-gakari and somewhat gorgeous. The boshi ranges from deeply tempered with a kaen-like tendency to midare-komi turning in ko-maru.

The NBTHK assessments consistently praise the excellence of Yoshitsugu's forging, noting that even among his own works certain examples are conspicuous for the quality of the jigane. His blades are said to "excellently demonstrate the characteristics of this school," and their remarkably healthy condition is repeatedly commended. The preservation of ubu nakago with long mei in fine chisel work is noted as valuable reference material. With pieces held in the Imperial Collection presented to Emperor Meiji by the Mori family, Yoshitsugu occupies a distinguished position within the Aoe tradition as a smith whose dated, fully signed works anchor the chronology of the Naka-Aoe school.