Tsunemitsu is transmitted as either the son or a student of Masatsune, the progenitor of the school, and is thus situated at the very origin of the swordmaking tradition. His working period is placed in the late to early era, a time when the group was defining the classical form that would dominate Japanese swordcraft for centuries. Extant signed works by Tsunemitsu are exceedingly rare, lending particular scholarly value to each authenticated example.
The consistently describe a forging style rooted in mixed with , at times becoming o- with interwoven -- a grain structure that conveys what the examiners characterize as an archaic, or , quality. adheres across the surface, and stands out prominently, a hallmark of the early tradition. The is typically a shallow -based pattern into which , , and are combined; the tends toward tightness, with fine adhering thickly in the . One singles out the in 7 as "likely the finest example among Tsunemitsu's works," noting that despite a at the , both form and workmanship are of superior quality. His blades characteristically display pronounced with and a or , preserving the elegant proportions of the period.
As a smith of the Masatsune lineage working at the threshold of the period, Tsunemitsu's surviving blades offer a direct window into the formative phase of craft. The restrained yet technically accomplished character of his work, together with the extreme scarcity of signed examples, ensures that each blade bearing his occupies a place of enduring importance in the study of early swordmaking.