Kagemitsu was the son of Nagamitsu and the third-generation master of the mainline (chakuryu), following Mitsutada and Nagamitsu in the direct succession of what became the most prolific school in the history of Province. His documented working period spans more than thirty years, with extant dated works ranging from the Kagen era (1303-1306) at the close of the period through Kenmu (1334-1338) at the opening of the period. He is traditionally credited with perfecting the temper pattern -- a distinctive one-sided falling form of that became a defining hallmark of his mature style, appearing most frequently in his from the Showa era (1312-1317) onward. His blades were transmitted in the collections of major houses, including the Maeda of Province and the Kuroda of , and several bear appraisal inscriptions attesting to the esteem in which they were held during the period.
Kagemitsu's forging is consistently described as among the finest in the tradition, with multiple evaluations noting that in the excellence of his he at times surpasses even his father Nagamitsu. His characteristic is a tightly packed , often with extremely fine adhering thickly, minute , and vividly standing -- the combination producing a steel of remarkable clarity and moist luminosity. In , his works are generally calmer and less flamboyant than Nagamitsu's, typically presenting a -based construction into which , , and angular elements are mixed, frequently with a (reverse-slanting) tendency; in other works, serves as the principal motif. The is characteristically tight, bright, and clear, executed predominantly in with accompanying . His often assumes the form known as the sansaku-, a gently undulating pattern turning back in that is regarded as distinctive to the three great masters. His shapes tend toward the standard or somewhat slender proportions of the late period, with high and , while his range from standard proportions to the larger-scaled forms that appear in his later dated works approaching the Kenmu era.
Kagemitsu occupies a pivotal position in the development of the school, serving as the bridge between the brilliant exuberance of Nagamitsu and the more disciplined, technically refined aesthetic that would define the mainline school's mature identity. His oeuvre is notable for the survival of a comparatively large number of -- a form relatively scarce among Nagamitsu's extant works -- and for the high proportion of signed and dated pieces that provide invaluable documentary material for the study of late swordsmithing. Several works attributed to his hand also bear (proxy signatures) by the closely related smith Chikakage, indicating an active workshop production system within the atelier. The consistent excellence of his forging, the originality of his innovation, and the (sound and well-preserved) condition in which many of his blades survive collectively affirm Kagemitsu's standing as one of the supreme masters of the tradition.