Sukemitsu (助光/助真) was a leading smith of the Yoshioka school in Province, active from the late into the early period. The lineage — so called because its smiths cut the character "一" () into the tang — flourished through the and periods at Fukuoka, Yoshioka, and Iwato. Among these branches, the Yoshioka prospered second only to the Fukuoka . Sukemitsu is regarded as the foremost smith of the Yoshioka group, and his fellow practitioners — Sukeyoshi, Sukeshige, and Suketsugu — all share the generational element "" (助). He held the court title Sakonshōkan, and dated works survive from the Einin, Gen'ō, Genkyō, Karyaku, and Gentoku eras. A separate, earlier Sukemitsu of the Fukuoka school, sometimes called , was summoned by the shogunate and became a pioneer of -based smithing.
Sukemitsu's works characteristically display mixed with , with very fine and abundant ; stands out prominently. His is typically a mixed with and , showing marked undulations and a flamboyant pattern, with frequent and , fine , and touches of and . The tends toward tightness with , appearing bright and clear. While some examples retain the comparatively flamboyant large-pattern tempering reminiscent of the Fukuoka manner, in general many works show smaller-scale workmanship where stands out within the — a distinguishing hallmark of the Yoshioka school.
The consistently praises Sukemitsu's work for refined and meticulous forging, bright , and flamboyant irregularity of temper pattern. Blades are frequently described as — sound and well-preserved — in both and , with "fine workmanship" and "excellent overall appearance." His signed and attributed works constitute valuable reference material for the study of the Yoshioka tradition, and they demonstrate the high technical standard that placed this school among the foremost lineages of the period.