Omi no Kami Tadatsuna, the second generation, was the son of the first-generation Omi no Kami Tadatsuna of Settsu Province. He later succeeded as nidai and adopted the celebrated art-name Ikkanshi (一竿子). In his early period his work closely followed his father's manner, frequently producing with well-aligned and long . As his style matured, he expanded into , billowing toran-style tempering, and even , demonstrating a breadth of repertoire rare among Osaka smiths. He was, moreover, "particularly skilled at , executing carvings that do not harm the blade itself and are in good overall harmony with it" -- a phrase the repeats with near-liturgical consistency across his designations. Active primarily during the Genroku through Hoei eras (ca. 1688-1710), his working life coincided with the zenith of Osaka craftsmanship.
The hallmark of Ikkanshi Tadatsuna's work is a tightly forged upon which "extremely fine adheres thickly" and "fine enter." His signature tempering begins with a at the base, above which the develops into a toran-style mixing , -, and -like elements. Within this undulating pattern, "long enter well," "runs overall," and cut through the -- a conjunction the identifies as the decisive marker of his hand. The is characteristically "bright and clear," with deep and thickly adhering . His works, though less celebrated, display their own diagnostic signature: "long run mixed among within the ." The carved on both sides of his blades -- , , sanko--, and his favored - -- are invariably described as "dense, forceful, and splendid," executed with meticulous precision. His rare forms are "extremely few" and "precious as reference material."
Across his designated works, the consistently praises the manner in which "both and are bright and clear" and the way his toran-style tempering achieves a "splendid, boldly patterned" effect "filled with spirited vigor." Several conclude that his blades are pieces "in which Ikkanshi Tadatsuna's full capabilities are expressed without reserve." The carving master Fujita Chozaemon Michii is identified as his teacher in blade carving, yet surviving works by Michii "are extremely rare," making Tadatsuna's jointly carved pieces valuable for understanding the lineage of Osaka traditions. From the calligraphic evolution of his signature characters, the dates his adoption of the Ikkanshi name to approximately Genroku 2 (1689), and his finest works span the decade that followed -- a concentrated period of mastery in which form, tempering, and carving achieve what the examiners term a "balanced accord."