The school emerged in Province during the mid- period, centered around the smith Morie, who is traditionally placed as a contemporary of Mitsutada. According to prevailing scholarly views, Morie was succeeded by his son Mamori—also known by the honorary title Samon no Jō or Umanojō—whose dated works from the Kenji, Kōan, and Shōō eras establish his active period in the late . The lineage question remains a subject of continuing research: while many authorities distinguish a first-generation Morie (contemporary with Mitsutada) from a second generation (contemporary with Nagamitsu), some scholars advocate a single-smith theory. Mamori himself appears to have worked across two generations bearing the name, though clear distinctions based solely on signature forms remain elusive. The smiths resided at in Province, and their workmanship, while sharing much in common with the broader tradition of the period, developed distinctive characteristics that set them apart from their more famous neighbors.
The is characteristically forged in mixed with , frequently exhibiting a pronounced tendency toward (standing grain), with extremely fine adhering thickly and fine entering throughout. Vivid —often described as mottled or standing clearly—is a hallmark feature that immediately identifies workmanship. The is predominantly with frequent intermixture of the school's signature motif: (tadpole-shaped ), characterized by rounded heads constricted at the base, creating a distinctive waisted appearance. This pattern is tempered in with adhering, and is enriched by vigorous and , appearing here and there, and frequent fine and running through the . Compared to Morie's more flamboyant and large-patterned work, Mamori's tends toward somewhat smaller-scale compositions, though both smiths demonstrate considerable variety in their output—ranging from brilliant to calmer -toned character with intermingled.
The school's technical mastery is evident in the refinement of their forging, with well-tempered blades that remain remarkably (sound and well-preserved) despite the passage of centuries. Their work demonstrates a high level of forging technique even in large blades, showing not the slightest looseness or slackening in either or . The distinctive combination of standing , vivid , and the emphatic use of creates an immediately recognizable style that, while related to the mainstream tradition, possesses its own archaic dignity and visual interest. Extant examples preserved in distinguished collections—including works transmitted in the Tokugawa, Kuroda, Asano, and Ō-Shimazu families—attest to the school's historical esteem and the enduring appeal of their varied and technically accomplished blades.