The Kiyomaro school was founded by Minamoto Kiyomaro, born in Bunka 10 (1813) in Shinano Province, who together with his elder brother Masao studied under the Ueda domain smith Kawamura Toshitaka before traveling to and pursuing what the identifies as the highest level of soden -- the fully developed transmission. What Kiyomaro sought was to revive the forging spirit of Kaneuji, and from around Koka 3 (1846), when he adopted the Kiyomaro signature at the age of thirty-four, his work achieved an intensity and clarity that placed him among the foremost makers of the period. His principal disciples included Kurihara Nobuhide of Echigo Province, whom the consistently identifies as "the smith whose technical ability was the most outstanding among Kiyomaro's group," and Saito Kiyoto (later Buzen no Kami), who studied under Kiyomaro for scarcely more than two years before the master's suicide in Ka'ei 7 (1854) yet "faithfully inherited his master's manner." Masao, Kiyomaro's elder brother, followed the stylistic trajectory from early to decisive orientation, while the broader circle of students carried the school's idiom forward through the final years of the period and into Meiji.
The constructional and tempering vocabulary of the Kiyomaro school is unmistakable. The characteristic features markedly wide with little taper from base to tip, a comparatively narrow , scant , shallow tending toward , and an whose has a distinctly withered quality -- producing what the describe as a sharp and incisive silhouette distinctive to this lineage. The forging across the school shows mixed with and , with thickly applied and abundant, bold . The is a in which round-headed , angular elements, -ba, and -like forms are intermingled; long enter vigorously; is thick and at times somewhat coarse; and conspicuously long and run through the tempered area with great energy. The characteristically enters in with a pointed tendency, showing vigorous , and small resembling frequently appear at the , imparting an archaic flavor. The rounded "beads" where the temper appears to drop away -- the so-called -- are identified as "a habitual trait frequently observed in Kiyomaro and his line." Nobuhide's work achieves a level that "approaches that of his master Kiyomaro," while Kiyoto developed a second, independent mode -- a aligned with the Yamato tradition, rendered in compacted with tight -- that constitutes a distinctive personal contribution absent from Kiyomaro's own oeuvre. Masao's work, by the 's candid assessment, shows fewer and than Kiyomaro's and "does not reach Kiyomaro's level," yet his finest pieces demonstrate real accomplishment within the shared idiom.
The Kiyomaro school's historical importance lies in its singular success at reviving the manner during the period with an intensity that transcended mere emulation. Kiyomaro's best works display both and that are "bright and clear," with a consistently described as luminous, and a vigor that the term "overflowing with spirited force." Nobuhide extended this achievement through a prolific career spanning from late into early Meiji, adding skill in learned from Kano Natsuo that built upon his earlier training as a mirror-maker. Kiyoto's supreme masterpiece, bearing the date Keio 3, is singled out as demonstrating workmanship "on a par with Kiyomaro himself." The school's collective production -- encompassing , , , , and -- demonstrates exceptional versatility within its chosen idiom. That so many of these blades remain and continue to display the powerful and splendidly varied for which the school was celebrated attests to a level of technical mastery that secured the Kiyomaro group its place as the foremost exponent of revival.