Kanenaga is traditionally regarded as the founder of the school, one of the Five Schools of Yamato. The smiths are understood to have resided outside the Tengaimon, the western main gate of Todai-, and to have maintained a close, subordinate relationship with that great temple. Sword reference works place the first-generation Kanenaga around the Shoo era (1288--1293) of the late period, though the has repeatedly noted that "in view of the workmanship and construction, it is also conceivable that his activity extends further back in time." A key chronological anchor is the survival of a dated by Kanekiyo -- transmitted as either the son or student of the second generation -- bearing a Karyaku 4 (1329) inscription. Thereafter the name Kanenaga was inherited through several generations, with extant works continuing into the and periods. Among Yamato smiths, comparatively many signed by Kanenaga survive, most in condition retaining a boldly cut two-character signature near the tip of the tang, yet examples remaining are exceedingly rare.
The defining technical hallmark, affirmed across every examination, is that "both and appear bright and " -- clear, vivid, and luminous. Among signed works of the Yamato Five Schools, Kanenaga is singled out as producing "the most strongly -laden tempering"; the granules are characteristically "rounded, brilliantly lustrous, and beautiful," at a level the has judged "can rival the finest masters of ." The forging is typically a tightly worked mixed with tending toward near the edge, laid with thick and interwoven with , frequently exhibiting . The is predominantly -based with shallow , incorporating , uchi-noke, , , and along the , with and running throughout. The characteristically runs straight with , often finishing in . Two general types are recognized: comparatively subdued examples with low tempering height, and more animated works "with a higher temper and differing between and " -- the latter typified by the celebrated "Kotekashiwa Kanenaga." Construction consistently features a high and wide , with many blades exhibiting "a dignified and elevated air in their overall form, which is also counted among their principal attractions."
Kanenaga occupies a position of singular distinction within the Yamato tradition. The consistently identifies his works as standing apart from general school production: attributions to Kanenaga specifically, rather than merely to "," are reserved for blades in which "the tempering shows especially conspicuous undulations and variation, the is notably strong, and the bright, beautiful stands out." His is described as showing "notable clarity" and a "deeply bluish" steel color of excellent refinement, with a combined tonal complexion -- -ai -- that is "extremely fine." Several designated examples bear illustrious provenance, including blades transmitted through Honda Tadatoki, grandson of one of Tokugawa's "Four Heavenly Kings"; the Sakai family of Himeji; and the hereditary retainers of the Satake house, with appraisals by both Kochu and Koson attesting to longstanding connoisseurial esteem. Across the full body of examined works, the recurring evaluative language is consistent: Kanenaga stands foremost among the Yamato school, his works distinguished by an exceptional brightness and clarity of that elevates them to the highest standard of the tradition.