Yoshimochi is transmitted in the as a swordsmith of the Fukuoka school of Province, descended from the lineage of Sukeyoshi. Reference works on signatures record him as the son of Sukeyoshi — though one source names his father as — and place his working period around the Bun'ei era (1264–1275), in the mid- period. The has noted that he is "probably to be regarded as active in the period as Nagamitsu and related makers," suggesting his dates may be slightly later than traditional accounts indicate. Signed works by Yoshimochi are exceedingly rare, numbering "likely fewer than ten," and among them the preserved at Taiseki- (Important Cultural Property) is especially well known for its dignified, commanding presence and flamboyant temper. He is regarded as "the next most skilled specialist after Yoshifusa"; however, unlike Yoshifusa, he does not produce large-pattern , instead tempering "in a highly technical manner."
The consistently characterizes Yoshimochi's work as displaying a comparatively calm and gentle manner in which "the rises and falls of the are not conspicuous." His is typically somewhat slender with pronounced , presenting what the board terms an "elegant silhouette" or "elegant ." The shows mixed with , with fine and delicate appearing frequently, while vivid stands out as a constant hallmark. The is grounded in mixed with and — a "small-patterned " with "little overall undulation" — enriched by abundant and , with adhering , fine , and producing "an expressive effect within an otherwise gentle overall pattern." The tends toward a tightened appearance and is described as bright and clear. The typically enters as forming with an extremely shallow turnback. His signature is consistently rendered as a small, two-character inscription positioned close to the , in which the character "" (用) is distinctively vertically elongated — a feature the repeatedly identifies as "typical for this smith."
Across the corpus of designated works, the returns to a core evaluative vocabulary that defines Yoshimochi's place within the Fukuoka tradition. Blades are praised as — "sound and well-preserved" — with forging of seiryo, "excellent-quality steel." The recurring judgment is that his work "clearly demonstrates the workmanship of this smith within the Fukuoka tradition, characterized by a relatively gentle manner," distinguishing him from the more flamboyant expression of his school contemporaries. While some works — notably the Taiseki- and certain unsigned attributions — display conspicuously large or flamboyant patterning, the treats these as the exception that proves the rule, affirming that "this constitutes an individual characteristic of his workmanship." His distinctive restraint, the technical refinement of his , and the consistency of his small-scale signature together mark Yoshimochi as a master of controlled subtlety within one of the most celebrated schools of the period.