The Naoe school (直江志津) represents the direct continuation of the lineage founded by Saburō Kaneuji, one of the most celebrated of the Masamune jittetsu — the Ten Great Disciples of Masamune. After Kaneuji settled in the district of Province and established his distinctive synthesis of methods with elements of his Yamato origins, his foremost students — Kanetsugu, Kanetomo, Kaneshige, Kanenobu, and others — subsequently relocated to Naoe within the province and continued forging in the manner of their master. It is from this geographic migration that the school derives its appellation: when one speaks of "Naoe ," it signifies the post-Kaneuji generation of -lineage smiths working at Naoe from the mid- period onward. Kanetsugu, traditionally identified as either a son or a direct disciple of Kaneuji, is recognized as the first-generation smith of the Naoe group, with signed works bearing dates from the Kannō era (circa 1350) establishing the school's chronological foundation. Kanetomo, another representative figure, carried the tradition across multiple generations extending into the period, ensuring the lineage's continuity well beyond its founding era.
The collective workmanship of the Naoe school operates firmly within the tradition yet exhibits a coherent set of distinguishing features that mark it as a recognizable subgroup. The forging () characteristically presents mixed with and , frequently showing a tendency toward standing grain — a -inclined quality inherited from Kaneuji's own Yamato-inflected steel. Thick adheres pervasively throughout the ground, with abundant entering to produce a steel that is notably — bright and clear. In the tempering, the school's smiths favor combined with , rendered in , with the rounded heads of the characteristically becoming linked in a clustering, sequential manner. Pointed forms appear interspersed within the temper pattern, and in the finest examples these elements combine with vigorous , , and running profusely through both and , producing a powerful scenic effect. The tends toward a deep, bright quality with fine well adhering — a feature the consistently praises across the group's attributed works. The is typically or , turning back in with , often exhibiting a vigorous -laden character that reinforces the commanding impression of the blade's upper section. When working in the format — broad, slightly elongated, with thin and shallow curvature — the school's smiths produce pieces that faithfully reflect the prevailing Enbun–Jōji aesthetic of the period.
The scholarly significance of the Naoe group lies in its role as the principal vehicle through which -influenced swordmaking took permanent root in Province, laying the groundwork for the later - tradition that would come to dominate Japanese sword production in the period. Signed works by any member of the group are exceedingly rare and constitute invaluable reference material — Kanetsugu's dated Kannō 1 and Kanetomo's Important Art Object serve as essential touchstones against which unsigned attributions are measured. The consistently affirms that the school's works display "the striking and distinctive style characteristic of the Naoe group," noting the well-forged with bright, clear and the characteristic interplay of linked , , and vigorous activity that distinguishes these smiths from both their predecessor and the broader tradition. Where Kaneuji's own work approaches most closely to Masamune's manner, the Naoe smiths transmit that inheritance with a subtly refined quality of their own — retaining the full vigor of forging while developing the linked and flowing grain tendencies into a recognizable collective identity that the treats as one of the most important regional expressions of -derived swordmaking.