Kunitoshi (来国俊) is traditionally regarded as the son of Kuniyuki and occupies a pivotal position within the Yamashiro school as the first smith to adopt the character "" (来) in his signature, a practice thereafter followed by all subsequent members of the lineage. His active period falls within the late period, with dated works spanning from the Shoo and Einin eras through Genko 1 (1321), a range of roughly forty years. A longstanding scholarly question concerns whether works bearing the two-character signature "Kunitoshi" (niji Kunitoshi) and those signed with three characters as " Kunitoshi" are by the hand or by different individuals; the observes that "certain differences can be recognized between their respective styles, and from the standpoint of workmanship it is possible to distinguish them," though "in recent years, re-examination of workmanship and the written forms of the signatures has led to increasing acceptance of the -smith theory." A dated Showa 4 (1315) bears an inscription stating an age at death of seventy-five, placing his birth around 1241 and the Koan 1 (1278) date of the sole dated niji Kunitoshi work at an age of thirty-eight -- "chronologically, therefore, it would not be unreasonable even if they were the person."
The two signature groups are consistently distinguished by form and temper. Works attributed to niji Kunitoshi "often have a broad with powerful " and display "a flamboyant in which stands out prominently," a manner so vigorous it can be "mistaken for work," though "a point of difference lies in the strength of within the ." The of this group tends toward "a comparatively large-grained texture with a propensity for slight ," and may appear. By contrast, blades bearing the three-character " Kunitoshi" signature "are generally of slender or standard build with or " and present "either or a -based temper mixed with small-patterned irregularities; overall they commonly display a gentle and calm manner of workmanship." The forging across both groups shows tightly packed with "thickly adhering " in "extremely fine particles," with standing out and fine entering. The characteristically runs and "turns back in " with often deep -- "features characteristic of this smith." The of the three-character works commonly incorporates and , with Kyo sometimes mixed in, and fine and appear, producing a that is consistently described as "bright and clear." Kunitoshi is further noted for producing many , in contrast to niji Kunitoshi, whose "extant are limited to a single example."
Across the corpus, the consistently characterizes Kunitoshi's work as embodying "a characteristically Kyoto workmanlike style that is refined and calm," possessing "a sense of quality and dignity" in both and . Individual repeatedly underscore that the finest examples achieve a that is "bright and clear" (), that the steel color is "clear and bright," and that the forging is "exquisitely refined." The highest praise is reserved for blades in which both and are -- "sound and well-preserved" -- and where the internal activities of , , and produce what is termed "a splendid effect." Works of exceptional quality are further described as possessing "deep and appealing character" and "deep, lingering interest," language that places Kunitoshi among the most accomplished masters of the Yamashiro tradition. The repeated notation that his shows "a gentle, soft quality" distinguishes his temper from the more assertive schools, affirming his standing as the defining figure of the lineage's mature, courtly aesthetic.