Kunimitsu is traditionally transmitted as the son of Kunitoshi, the preeminent master of the school of Yamashiro Province. He was active from the closing years of the period into the early period; among extant works bearing production dates, the earliest is from Karyaku 1 (1326) and the latest extends to Kanno 2 (1351). The Kokon Meizukushi places the first generation in the Gentoku-Kenmu eras and the second around Koei, and judging from extant works this may be regarded as a reasonable view. Within the lineage, Kunimitsu is recognized as the smith with the broadest stylistic range -- an exceptionally versatile maker who left numerous works in both and .
His oeuvre is notably diverse. In addition to the classical, truly straight embodying the Kyoto tradition, he produced works in -based styles mixed with and ; works with a basis showing a slight inclination toward ; works in tone mixed with ; and pieces in which becomes the dominant pattern. His forging characteristically shows dense with thickly applied and , frequently accompanied by . The is consistently bright and clear, and within the one encounters fine and in profusion. Celebrated masterpiece such as the Yuraku , the Shiokawa , and the Ikeda further attest to the refinement of his technique.
Kunimitsu's significance within the Yamashiro tradition rests on his having successfully broadened the expressive vocabulary of the school while preserving its foundational elegance. His works spanning the Karyaku and Gentoku eras represent the period when his technique was at its most fully developed. The depth of quality and the moist, lustrous character of the remain hallmarks by which his work is appraised, and both signed and attributed examples consistently demonstrate the characteristic features that distinguish this master within the broader canon of Yamashiro smithing.