Kuninobu (延寿国信) was a leading disciple of Tarō Kunimura, the founder of the school of Province. According to the prevailing tradition, Kunimura was a maternal grandson of Kuniyuki of Yamashiro, and through this lineage the school inherited the working manner of the tradition. From within the group emerged many accomplished smiths — Kuniyoshi, Kunitoki, Kunisuke, Kunitomo, Kunitsuna, and Kuninobu among them — and the school flourished greatly from the late period through the era in the Kumafu area of Kikuchi District. Kuninobu's active period is traditionally placed around the Karyaku era (1326–1329). Despite his stature as one of Kunimura's senior pupils, extant works by Kuninobu are extremely few in comparison with those by contemporaries such as Kunitoki, Kunisuke, and Kuniyoshi.
The workmanship of the school tends not to display markedly individualized traits from one smith to another and in general resembles the school of Yamashiro; nevertheless, certain distinguishing hallmarks may be observed. In the forging, a conspicuous tendency toward appears within an base mixed with and , and a whitish stands out prominently. The is characteristically a carrying a shallow tendency, with and entering vigorously; the tends toward tightness and shows a somewhat quality, while the internal activities within the tempered area are comparatively calm. The is typically rendered with a somewhat fuller roundness at the tip and a shallow turnback, with some examples finished in . A particularly notable trait of the school is the manner in which runs along the edge — a feature that appears with special conspicuousness in Kuninobu's finest works. In the inscription of the character 国 (), the right half within the enclosure is cut in a distinctive "ear-shaped" manner shared across the group, and Kuninobu in particular shows a habitual tendency to cut the vertical stroke quite diagonally.
Among the rare surviving works by Kuninobu, those retaining tangs with original signatures are of exceptional value and serve as critical reference points for attribution. His best pieces exhibit a refined and polished quality of execution that surpasses the level typically encountered in work, with bright , dense , and fine contributing to a dignified and imposing presence. Comparison with the signed designated an Important Cultural Property, held in the Mitsui Bunko, confirms this elevated standard. Works attributed to Kuninobu frequently display ample and a state of preservation, together with a silhouette that evokes the manner of Kunimitsu — testimony to the enduring connection between the school and its Yamashiro homeland tradition.