Sukemitsu held the court title Sakon-no-shogen and signed in full beneath the school's single character ichi: Bizen no Kuni Yoshioka-ju Sakon-no-shogen Ki-no-Sukemitsu. He is the representative smith of the Yoshioka Ichimonji, the Bizen Ichimonji branch that, as the published sources put it, prospered from the end of Kamakura into the Nanbokucho period second only to the Fukuoka Ichimonji. The school takes its name from the character ichi cut on the tang, and its representative hands share the suke 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 Kamakura period, and several of his tachi 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 tachi of the 26th session the jigane is an itame mixed with masame in which an utsuri stands. Over it he sets a suguha-toned line into which ko-choji and ko-gunome are mixed, nie adhering, the boshi running straight to a yakizume 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 choji that can be mistaken for Fukuoka. A tachi dated Karyaku 2 shows the same restraint: a calm temper of choji mixed with gunome over a jigane where midare-utsuri stands, which they say shows the Yoshioka Ichimonji style well. The National Treasure naginata dated Gen'o 2 keeps the same line, ubu and of the wide, unswelling shape typical of Kamakura naginata: a wide choji mixed with gunome over a ko-itame with midare-utsuri, turning to suguha toward the monouchi, the nioiguchi tight, a temper its text calls plainer than Fukuoka with the gunome prominent, 「福岡一文字より地味で互の目が目立つ」.
The jigane is the constant across his work. A well-forged itame, at times tightening into ko-itame or mixed with mokume, carries ji-nie, and on the finest piece chikei enter frequently. A clear midare-utsuri is named on three of his four Juyo blades, signed and attributed alike. The fourth, the 26th-session tachi, has the utsuri standing over its itame mixed with masame. The nioiguchi is bright and tends to tighten, the activity carried in ashi and yo, and a bo-hi is carved on three of the four. Of the Karyaku 2 tachi the published commentary writes that both ji and ha 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 choji-midare. The published sources record that some of his work carries large-pattern choji that at a glance can be mistaken for the Fukuoka Ichimonji, 「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 midare 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 gunome stands out within the midare. Its signed exemplar is the National Treasure tachi dated Genko 2 (1322), long and grand, a large choji-midare mixing kawazuko-choji, fukuro-choji and gunome over an itame with midare-utsuri; 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 Juyo record the flamboyant face belongs to the two attributed katana, while the two signed tachi keep the calmer line. The kinzogan-mei katana, greatly shortened and inlaid in gold with his name, shows it on a dense ko-itame with standing midare-utsuri, choji mixed with gunome. The published sources call its workmanship 「華麗な丁子の出来が頗る見事」, a splendid choji that is superb. The mumei katana attributed to him goes further. Its itame mixed with mokume carries very fine, thick ji-nie and abundant chikei. The choji-midare mixes gunome and pointed ha in a lively pattern, with fine tobiyaki, kinsuji and sunagashi, and the yakihaba narrows a little toward the monouchi.
What sets Sukemitsu apart within his lineage is this division, and the fact that both faces rest on the same Yoshioka jigane. He is held apart from Fukuoka by scale rather than by kind. His bright midare-utsuri and his small, gunome-marked choji 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 mumei katana the published sources write that its ji and ha support the old attribution, judging it a superior work of the Yoshioka Ichimonji, 「吉岡一文字の上作」, the meticulous forging especially noted. His dated and signed tachi anchor the school's standard, the fixed points against which the mumei attributions are measured.
Sukemitsu's record reaches the highest ranks of the designation system. Two signed works are National Treasures: a naginata dated Gen'o 2 (1320), recorded with Maeda family provenance, and the long-signed tachi dated Genko 2 (1322), which carries a provenance through Tokugawa Iemitsu and Abe Tadaaki. His Important Cultural Property is a kinzogan-mei katana shortened by Hon'ami Kotoku. The Tokugawa Art Museum is also recorded among the holders of his work. Four blades carry the Juyo rank: the two signed tachi, the gold-inlaid katana with its mid-Edo gold nashiji mounting bearing aoi crests, and the attributed mumei katana. A signed hira tanto dated Genko 4 (1324) is recorded in Honma's inventory of the Imperial collection: an itame flowing into masame with midare-utsuri, a gunome mixed with choji and covered in nie. Honma notes that tanto by any Ichimonji smith, not only Sukemitsu, are exceedingly rare[[c:1]], 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 Juyo pieces are few, and of recorded whereabouts most are long held rather than traded. The Fujishiro appraisal places him at Jo-jo saku. A signed Yoshioka Ichimonji Sukemitsu coming to light is a landmark when it happens, a document of how the Yoshioka kept the Ichimonji manner alive at the close of the Kamakura age.