This piece is signed Heianjō Minamoto Nobuyoshi (平安城源信吉), one of the prominent masters of the Osaka Shintō school active in the early Edo period around the Kanbun era (circa 1661–1673). The younger brother of the first-generation Shinano no Kami Nobuyoshi of Kyoto, he later moved to Osaka where he became one of the representative smiths of the flourishing Osaka Shintō movement, working in the same generation as Tsuda Echizen no Kami Sukehiro and Inoue Shinkai. Osaka Shintō of this period is regarded as a technical peak of early Edo swordsmithing, known for refined forging and controlled, elegant tempering.
The blade measures 58.5 cm. The jihada is a tight and well-forged itame-hada, showing the dense and carefully worked steel typical of Osaka workmanship. The hamon is a composed suguha, precise and restrained. Approximately 9 cm below the tip there is a small but sharp-edged nick along the cutting edge; its shape strongly suggests blade-to-blade contact rather than accidental damage, indicating that the sword likely saw actual use.
The sword is mounted in Type 98 guntō koshirae with leather-covered field mounts, reflecting the common wartime practice of remounting earlier Edo-period blades for military service.