Steel "bright and clear," with thick and entering frequently, is the constant the returns to in nearly every blade of this phase, and it marks the moment the tradition reached its summit in . The chapter opens when Kunimitsu carried the refined and restrained of the line into and began laying more thickly across both and ; from that foundation the tradition advanced through Yukimitsu and reached its peak in Masamune, whom official records place "at the very summit." The sampled blades cluster around the masters who carried this manner forward: Go Yoshihiro of Matsukura-go in , counted among the Masamune Juttetsu and represented here by numerous , and the smiths Hiromitsu and Akihiro, who stand "next after Sadamune" and extend the phase with dated works running from Enbun 2 (1357) to Shitoku 4 (1387). The window spans late proportions through the broad Enbun-Joji forms of the fourteenth century.
The phase reads as mixed with , often tending toward standing or flowing grain, carrying very fine laid thickly with threaded densely throughout; over this the is founded on mixed with , , and a flavor, with deep , thick , and and running well, the bright and clear. This is precisely the distance the school traveled from its roots: where that foundation held a tight, restrained , the Go break into wide , , and (one records that "gathers, thickens, and congeals"), with a tempered so deeply it becomes and sweeps in . Go himself sits one step calmer than Masamune and Norishige, his and more reserved but his and a step brighter, the often -inclined; one wide- example with shows how close the quiet end of his range stays to the Kunimitsu manner. The turn is sharper still: Hiromitsu and Akihiro orchestrate through intermingled and over gunome-chōji, including the round-headed dango-chōji, on wide and , an effect "not seen in earlier works." Here the classic phase divides from the later Sue- continuation, whose smiths inherited the vocabulary without the depth of and clarity of steel recorded in these blades.
A collector separates this phase because it holds the recognized masters at full strength. Go achieved the highest designation through the unmistakable brightness of his alone, despite no surviving signed works, and the sample carries the weight of that reputation: the Nakagawa-Go owned by a retainer of Oda Nobunaga and later the Tokugawa house, the "-giri" Go inlaid by appraisal, the Okubo-Go transmitted in the Odawara Okubo family, and blades held by the Uwajima Date and Kuroda houses, with names recorded in the Kyoho -cho. The points are concrete and repeated: Go's active , tendency, and ; Akihiro's dated five-character " Akihiro" signatures, whose shift from full to abbreviated dating after Eiwa lets a viewer place a blade in time; and the near-indistinguishability of Hiromitsu and Akihiro, parsed only by scale and the prominence of dango-chōji. These are the works that define the apex, against which both the foundation and the Sue- aftermath are measured.