The Sue- school (末相州) represents the final flowering of the Province forging tradition, carrying the legacy of Masamune and his immediate successors -- Hiromitsu and Akihiro -- through the period and into the Azuchi- era. Where the great and masters had established the - as the most technically demanding of the Five Traditions, the Sue- smiths sustained and adapted that idiom across generations of changing martial demand. The school's principal figures -- Tsunahiro, Hiromasa, Hirotsugu, and Masahiro -- maintained an unbroken succession in and its environs, with Tsunahiro's lineage extending through at least five generations from the Tenbun era into the Meiji period. Masahiro, traditionally transmitted as descending from Masamune's youngest son with dated works from the Joji and Meitoku eras, bridges the and periods; one tradition even holds that the fourth-generation Masahiro changed his name to Tsunahiro, underscoring the interconnected nature of these late lines.
The collective technical identity of the Sue- school is anchored in bold (full-temper) work of striking force and visual complexity. Across the school's members, the forging characteristically displays mixed with , with the grain tending to stand and showing abundant and . The favors incorporating , , and -shaped elements within a ground, and through conspicuous and the tempering develops into the effect that defines the school's identity -- crescent-shaped islands of tempered steel spreading across the blade surface in Tsunahiro's work, robust -laden compositions "calling to mind the Hasebe school of the period" in Hirotsugu's blades, and -like tempering connecting Masahiro's output to the Hiromitsu and Akihiro circle. and run through the tempered areas, and the tends toward tightness. In construction, the school favors wide and extended in , while overwhelmingly adopt with broad proportions and pronounced . A further distinguishing feature of the school is the consistent presence of accomplished -- , grass-style , -sho, , hatahoko, and devotional inscriptions, often executed in raised relief () -- that constitutes a defining element of late production and appears with remarkable frequency across all of the school's principal smiths.
The Sue- school's significance lies in its role as the custodian of the most technically ambitious forging tradition in Japanese sword-making during a period of transition. Tsunahiro, as the foremost representative of the school's final phase, produced an extensive body of work including blades forged in the Tsugaru domain -- the so-called "Tsugaru-uchi," some inscribed "within three hundred " -- that constitute important historical documentary material. Hirotsugu's finest pieces rank among the most vigorous achievements of late craftsmanship, with described as forceful even into the . Masahiro's early-generation blades in with and proportions preserve the characteristic -period form, while Hiromasa's output bridges the lineage of Province with the mainland tradition. The 's evaluative language is consistent: these smiths displayed "both the period character of workmanship and the traditional manner of the -," producing blades that are frequently -- sound and well-preserved -- with workmanship rated as excellent and of upper-level quality. In an era when many provincial traditions diluted or abandoned their founding idioms, the Sue- school preserved the essential character -- the powerful , the dramatic , the accomplished carvings -- transmitting it faithfully to the end of the feudal age.