When the Fukuoka workshops gave way at the close of the thirteenth century, the line carried on at Yoshioka in , and the place this branch "in place of the Fukuoka ," flourishing from the end of into the era. The Yoshioka smiths shared the character (助) as a generational element, and the records name Sukemitsu, Sukeyoshi, Sukeshige, Suketsugu, Sukeyuki, Sukehide, and a second Sukeyoshi (助義). Sukemitsu is identified as the leading hand of the group, with dated work surviving across the Einin, Gen'ō, Genkyō, and Karyaku eras; Sukeshige left blades dated to Enkyō and to Jōwa 2 (1346), and Sukehide a dated Shōhei 18 (1363). Suketsugu, dated Eitoku 2 (1382), is the smith whose recorded move from Yoshioka to marks the point where this branch fed into the tradition. Allied groups resident nearby, the Iwato of Yoshiie and Muneuji and the Nitta-shō smith Chikatsugu, belong to the late-period current.
What separates Yoshioka work from the Fukuoka apex is a matter of scale and temperament. The state plainly that large-pattern, splendid in the Fukuoka manner survives only rarely; the customary mode is "a somewhat smaller-scale workmanship in which stands out within the ." Several blades rest on a or base carrying and , the undulations showing little conspicuous rise and fall, as on Sukeshige's where the are "aligned and uniformly tempered." A reverse-slanting () tendency appears at times, and the temper often tightens toward the . The forging is a tightly grained , sometimes with , carrying fine , , and a clearly standing . Where Fukuoka layered and fukuro-chōji in flamboyant rise and fall, Yoshioka holds the pattern to a quieter register, and the repeatedly note that the in with a round turn and the calm, regular tone "resemble contemporaneous work," the manner of the period drawing the branch toward regularity.
The value lies in reading that restraint correctly. Against Fukuoka, the discriminators are the reduced scale of the clove pattern, the asserting itself within the , the -leaning compositions with entering , and the bright, -dominant with accompanying and occasional and . The named masters anchor these readings: Sukeyoshi's mixed with and narrowing temper, attested by a Chōshiki gold-inlaid ; Sukemitsu's more flamboyant with and , carried on an held by old tradition; Sukeshige's round-headed with even undulation. Suketsugu's late , hardening open, waisted , points ahead to the Ōei- style that followed. Among the documented provenances, the Iwato smith Minamoto Yoshiie's of Mototoku 2 (1330) was bestowed on Yoshikawa Hiroie as a memento of Toyotomi Hideyoshi, and several Yoshioka and Tsunetsugu blades carry , a reminder that earlier appraisal sometimes folded such work into "" before the modern separation of the two Tsunetsugu lines.