The school takes its name from the locality of in Province, a subdivision within the village of where its founder Moriie maintained his forge. The lineage begins in the mid- period, with the prevailing view positing two generations bearing the name Moriie — the first regarded as a contemporary of Mitsutada, the second as active alongside Nagamitsu — though a clear demarcation between them remains a subject for future research, and there are scholars who advocate a single-smith theory. The earliest dated extant work bears the inscription Bun'ei 9 (1272), and signed examples extend through the period. No blade by Moriie or his followers — including Sanemori, Mitsumori, Morishige, and Morinaga — has been found signed "-ju"; instead they inscribe "-ju," reinforcing the understanding that was an administrative ward within the broader smithing district rather than a separate center. Through Moriie's pupils, particularly Morishige and his son Motoshige, the line continued to exert influence on production well into the period and beyond, with later generations of Morishige working under what reference works identify as the group.
The defining technical signature of the school, affirmed across every examination of its members, is twofold: a that tends conspicuously toward — standing grain that imparts an active, textured surface — and exuberant (蛙子丁子) within the tempered edge. The forging is typically mixed with , upon which fine adheres thickly and enter with frequency, while vivid rises throughout the blade. The is characteristically , within which , -, , , and elements tending toward appear in varying combinations. The temper is with , enriched by and , and the is characteristically bright and full, often conveying a soft, quality. Within this shared idiom, individual voices can be distinguished: Sanemori's irregular patterning tends toward a somewhat smaller scale than his father Moriie's, with tempering that does not show the pronounced rises and falls; Mitsumori achieves a wider with a particularly ornate, deeply splendid character; and Morishige's later -period works tend toward a more subdued, composition with intermingled and a that tends toward tightness. By the period, Morinaga introduced a vigorous, -rich idiom — the so-called Soden style — in which the exuberant and -like suggest connections beyond the group to the broader currents of Chogi and Motoshige.
The school occupies a distinguished position within the tradition as a collateral lineage whose pronounced standing grain and flamboyant establish a distinct artistic identity alongside the mainline masters. Moriie himself is recognized as possessing an unusually wide range — from gorgeously disordered works in which large clusters become dramatic formations to comparatively calm pieces tempered in quiet mixed with that exude what the describes as "a subdued, austere flavor." His oeuvre spans an exceptional variety of forms including , , , , , and the exceedingly rare . Sanemori's best works have been termed "white eyebrow" pieces exhibiting notably exceptional workmanship, while Mitsumori's flamboyant and brilliant place him among the most accomplished smiths of the late tradition. That Morishige's later descendants were eventually absorbed into the broader mainstream — their workmanship assimilating the character of the Nagamitsu group — attests to both the permeability of workshop boundaries and the enduring influence of forging conventions upon the wider tradition. Throughout the school's production, the consistently praises works for ample , sound preservation, and a combined quality that, at its finest, achieves what examiners describe as "splendid in effect yet overflowing with dignity."