Kunihiro belongs to the school of Province, a lineage that emerged in the early period and broke decisively from the conventional, tradition-bound sphere of earlier Kyushu workmanship. The school's progenitor, O- ( Yukihiro), established a refined style in which both and appear bright and clear, and Kunihiro faithfully succeeded this manner alongside fellow smiths Yasuyoshi, Yukihiro, Yoshisada, Hiroyuki, Hiroyasu, and Sadayoshi. Kunihiro is transmitted in some accounts as a son of Yoshihiro, and according to another theory as a son of Sadayuki. The records his place of residence as Ikihama in Chikushu, and a signed bearing the date Shohei 12 (1357) confirms his period of activity, with further works extending to Shohei 17 (1362).
Two principal modes may be recognized in Kunihiro's work. The first features comparatively large-patterned -ba with as the main theme, in which the temper is taken at a high level — at times rising to the — producing a bold and vigorous effect. The second presents a more -based manner mixed with . In both modes, the forging displays mixed with , with thickly adhering and abundant . The characteristically shows deep with plentiful , and internal activities of , , and work vigorously throughout the hardened edge. The typically forms a slightly pointed with , turning back rather deeply. From old times, the family, when appraising works of the " ichirui" ( group), tended to assign the attribution of Kunihiro specifically to those pieces displaying the most vigorous and exuberant .
The has consistently affirmed that Kunihiro's works "clearly display the characteristic manner of the group," while distinguishing his hand by the particular boldness and power conveyed through broad and large-patterned temper. Both and are noted for their rich variation, and the breadth of the — wider and narrower in alternating passages — combined with fluctuations in adherence, produces an effect of dynamic internal activity. Signed works remain uncommon, lending heightened documentary significance to each authenticated example. Within the lineage, Kunihiro stands as the smith to whom the most powerfully wrought blades are attributed, his work embodying the school's departure from earlier Kyushu convention and its achievement of a bright, vivid, and technically accomplished forging tradition.