Yoshimitsu (備前国長船義光) is commonly regarded as a son of Kagemitsu and a younger brother of Kanemitsu, situating him at the heart of the main line during its most productive era. His activity spans from the Genko era at the end of the period through the Joji era of the period -- approximately forty years -- placing his working life "largely in parallel with that of Kanemitsu." Unusually among the smiths, Yoshimitsu employed both Northern and Southern Court era names, as evidenced by a dated 6 (corresponding to Jowa 1), a detail the consistently highlights as noteworthy. His early style follows that of Kagemitsu, while works produced after the onset of the period resemble Kanemitsu, tracing a clear arc of stylistic inheritance through the school's greatest figures.
Yoshimitsu's technical signature is the resolution of into "a small-patterned design" -- a phrase that recurs across virtually every assessment and serves as the primary distinguishing criterion separating his work from that of Kanemitsu, whose irregularity is rendered in larger motifs. His is characteristically a tightly forged or mixed with , with extremely fine adhering thickly, fine , and vivid standing out -- a hallmark the examiners describe as "especially desirable." The is typically mixed with -like elements, , and angular forms, accompanied by and , with and working within the temper. The is consistently praised as "bright and clear," and works in the soden manner display strong with vigorous along the boundary. In his -period output, the inclusion of , reverse-slanting () tendencies, and within the small-pattern composition reveals an individuality that "is readily perceived as a hallmark of Yoshimitsu."
The repeatedly designates Yoshimitsu's finest blades as yuhin or shusaku -- terms reserved for work of the highest caliber -- and emphasizes that "although the forging is meticulous, it is also rich in rustic vigor." His signed and dated works are comparatively few, lending those that survive considerable documentary value for the study of the school. Blades bearing production dates, such as the Jowa 5 and the Sadaharu 3 , are singled out as "precious" and "extremely valuable" for establishing the chronological boundaries of his oeuvre. In the 's assessment, Yoshimitsu occupies a position of quiet distinction within the Kagemitsu-Kanemitsu lineage: a smith whose refined forging, varied yet restrained , and luminous represent "workmanship that can truly be called soden of upper rank."