Sukemitsu held the court title Sakon-no-shogen and signed in full beneath the school's single character : no Yoshioka-ju Sakon-no-shogen Ki-no-Sukemitsu. He is the representative smith of the Yoshioka , the branch that, as the published sources put it, prospered from the end of into the period second only to the Fukuoka . The school takes its name from the character cut on the tang, and its representative hands share the element, Sukemitsu named first among Sukeyoshi, Sukeshige, Suketsugu and Sukeyoshi. The dates the published sources record on his works run through Einin, Gen'o, Genko, Karyaku and Gentoku, the last decades of the period, and several of his keep part of the long signature legible.
His hand has two faces, and the published sources keep them apart. The fundamental Yoshioka manner is the calmer, smaller-scale temper. On a long-signed of the 26th session the is an mixed with in which an stands. Over it he sets a -toned line into which and are mixed, adhering, the running straight to a finish. The published sources read this blade as showing the true Yoshioka workmanship, 「吉岡本来の出来を示したもの」, even though his work also includes large-pattern that can be mistaken for Fukuoka. A dated Karyaku 2 shows the same restraint: a calm temper of mixed with over a where stands, which they say shows the Yoshioka style well. The National Treasure dated Gen'o 2 keeps the same line, and of the wide, unswelling shape typical of : a wide mixed with over a with , turning to toward the , the tight, a temper its text calls plainer than Fukuoka with the prominent, 「福岡一文字より地味で互の目が目立つ」.
The is the constant across his work. A well-forged , at times tightening into or mixed with , carries , and on the finest piece enter frequently. A clear is named on three of his four blades, signed and attributed alike. The fourth, the 26th-session , has the standing over its mixed with . The is bright and tends to tighten, the activity carried in and , and a is carved on three of the four. Of the Karyaku 2 the published commentary writes that both and are healthy and well made and that the signature is good reference material, 「地刃共に健全で出来がよく、銘は好資料」.
The other face is the high, flamboyant . The published sources record that some of his work carries large-pattern that at a glance can be mistaken for the Fukuoka , 「一見福岡一文字派に紛れるような大模様の丁子」. For the school as a whole they call that large-pattern the rarer manner, and the usual one 「乱れの中に互の目が目立ち、やや小出来となるもの」, a slightly smaller pattern in which stands out within the . Its signed exemplar is the National Treasure dated Genko 2 (1322), long and grand, a large mixing -, and over an with ; its text writes that the Yoshioka generally lack Fukuoka's splendour but that this blade is unusually flamboyant, 「珍しく福岡一文字に紛れるほどに大模様に乱れた華やかな作」. In his record the flamboyant face belongs to the two attributed , while the two signed keep the calmer line. The , greatly shortened and inlaid in gold with his name, shows it on a dense with standing , mixed with . The published sources call its workmanship 「華麗な丁子の出来が頗る見事」, a splendid that is superb. The attributed to him goes further. Its mixed with carries very fine, thick and abundant . The mixes and pointed in a lively pattern, with fine , and , and the narrows a little toward the .
What sets Sukemitsu apart within his lineage is this division, and the fact that both faces rest on the same Yoshioka . He is held apart from Fukuoka by scale rather than by kind. His bright and his small, -marked are the Yoshioka norm, and he reaches back toward the large pattern of the parent house only in part of his work. Of the attributed the published sources write that its and support the old attribution, judging it a superior work of the Yoshioka , 「吉岡一文字の上作」, the meticulous forging especially noted. His dated and signed anchor the school's standard, the fixed points against which the attributions are measured.
Sukemitsu's record reaches the highest ranks of the designation system. Two signed works are National Treasures: a dated Gen'o 2 (1320), recorded with Maeda family provenance, and the long-signed dated Genko 2 (1322), which carries a provenance through Tokugawa Iemitsu and Abe Tadaaki. His Important Cultural Property is a shortened by Kotoku. The Tokugawa Art Museum is also recorded among the holders of his work. Four blades carry the rank: the two signed , the gold-inlaid with its mid- gold mounting bearing crests, and the attributed . A signed dated Genko 4 (1324) is recorded in Honma's inventory of the Imperial collection: an flowing into with , a mixed with and covered in . Honma notes that by any smith, not only Sukemitsu, are exceedingly rare, and calls this one, though somewhat tired, good reference material. The National Treasures and the Important Cultural Property are heritage held in trust, not blades a collector encounters. The pieces are few, and of recorded whereabouts most are long held rather than traded. The Fujishiro appraisal places him at Jo-jo . A signed Yoshioka Sukemitsu coming to light is a landmark when it happens, a document of how the Yoshioka kept the manner alive at the close of the age.