Kunimitsu (来国光) of Yamashiro Province is traditionally regarded as the son of Kunitoshi, though some sources transmit him alternatively as one of Kunitoshi's disciples. He was active from the late 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), a span of twenty-five years that has given rise to a longstanding two-generation theory. If one adopts that view, works dated to the Kanno era would correspond to a second smith of that name; however, the chronological division between the first and second generations has not yet been clearly established and remains a subject for future research. Within the lineage, Kunimitsu's works survive in the greatest number, and like his father he produced many and . The earliest dated inscriptions by Kunitoshi conclude with Genkyo 1 (1321), while Kunimitsu's begin just five years later, placing him as the direct successor to the school's foremost master.
Kunimitsu's manner of workmanship is notably diverse, and he is regarded as the most versatile craftsman within the school. In addition to the traditionally orthodox for which the Kyoto tradition particularly excelled, there are works in a -based style mixed with and ; works of tone with a slight tendency; works of -based temper mixed with ; and also in which predominates. His forging characteristically shows tightly packed with thickly applied and , frequently exhibiting . The is consistently bright and clear across his oeuvre. His typically turns back in , often with . Activities within the are lively, with , , , and entering abundantly. Later-period works display a more robust construction with wider and extended proportions, reflecting the evolving tastes of the era. The calm yet technically accomplished tempering manner seen in his — particularly the with intermingled and — frequently calls to mind the observed in his , demonstrating a consistent artistic vision across blade forms.
Kunimitsu stands as the most prolific and wide-ranging master of the school, bridging the refined aesthetics of late Yamashiro tradition with the bolder sensibilities of the period. Signed from his later phase are few, lending particular significance to those examples that preserve portions of the original . His signature is characteristically cut with a thick chisel, with the radical of "" formed in an angular manner. Many of his blades survive in a remarkably (sound and well-preserved) state, with both and retaining exceptional clarity. The depth of feeling in the and of both and — that profound flavor that only Kunimitsu can achieve — together with his command of the full spectrum from serene to vigorous , secure his position as an exceptionally accomplished swordsmith whose breadth of expression remains unmatched among the masters of the lineage.