Yoshimune is a Fukuoka smith of mid- whose surviving signed work is so scarce that the published sources treat each designated blade as a record of a hand otherwise known chiefly through one famous piece. The best-known of his works is the preserved at Tsukubasan Jinja, an Important Cultural Property, and the institution names it expressly as such, observing that he "is represented by few extant works, the most famous being the held at Tsukubasan Jinja" (現存する作刀が少なく ... 最も著名なものとして筑波山神社蔵の太刀). The plate of that records it as signed Yoshimune, forged in and tempered in . The school itself, founded by Norimune, arose in the early period and flowered through the middle of it, and the published sources place this signature with the Fukuoka branch at exactly that peak, when the school reached its most brilliant and dynamic large . The name was carried by more than one smith, which is the central problem of his identity, but the blades judged his own are read consistently as the mature Fukuoka manner brought to full flamboyance.
His characteristic hand is a full with no quieter base beneath it. Over an he tempers a clove pattern mixed with small and , and on his finest works it rises into large tassel-headed ō-busa- and sack-shaped with pointed -ba mixed in, the undulating with marked height variation. and enter the freely, the runs deep with , and fine and play through it, the bright. The gathers this into the school's defining statement, that at the mid- peak "the magnificently developed style, brilliant and full of dynamism, of large is displayed in splendid fashion". It is this temper, never a -toned hand, that the appraisers use to part his blades from the quieter members of the same school.
The is the proper steel and the constant that holds across all of his signed work. The forging is an mixed with , tending a little toward standing grain (), with well risen and, on the most tightly forged pieces, fine entering. Over this stands a vivid , the speckled reflection of old steel, which appears on every blade the published record describes in full and is as much a part of the recognition as the temper above it. The answers the . On the and it is a small round (), at the point sometimes turning with a pointed tendency or a little , while on the flamboyant blade and on one further it runs into the point as a . Carving is rare but present, the of 2003 bearing a and a short with accompanying , and below them a cut kaki-nagashi.
The corpus draws a single mature manner pitched at two levels of display rather than a sequence of periods. On his prime works the clove pattern breaks into the large tassel-headed forms, and the shows the same large with and pointed elements over an with thick and fine ; the published sources judge such a blade to express the workmanship of the Fukuoka school at its height, finding that "the style of the Fukuoka school at its peak is well displayed" in its splendid "flamboyant of mixed with ō-busa-". On the the same hand runs at a smaller pitch, the mixed with and small rather than large clove, the and complete. A recorded in Honma's inventory of the Imperial collection runs at the same smaller pitch: a temper mixed with and over a slightly standing with , the running in with and . The inventory finds its manner "wholly that of the early school", and reads the slightly extended and the -led temper as signs that he worked later than Norimune and Sukemune. It dates him to the Jōkyū era and records the tradition that he was one of the smiths who forged in rotation for the cloistered emperor Go-Toba. The question of how many generations carried the name is left open: the published record states that registers list smiths of this name in the Jōkyū, Shōgen and Kōan eras and that "the precise division by generation remains a topic for further study".
His standing in the school is fixed by the reasoning that recovers his blades from the crowd of namesakes. Because the name was shared among , Fukuoka , Yoshioka and smiths, the appraisers sort each blade by its own workmanship and the manner of its signature, and they assign this signature to the mid- Fukuoka hand whose individuality showed most clearly in the brilliant large of the period. The judgment is made on the work itself: of the the published sources find that "both and strongly display the distinctive features of the Fukuoka school", the clear in the and the large sharp with height variation. He stands among the brilliant mid- masters of the mature Fukuoka school alongside Yoshifusa and Norikane, his bright and showy ō-busa- setting him with the flamboyant rather than the restrained side of the school, against the deliberately quiet of his schoolmate Yoshimochi.
Fujishiro grades him Jō-jō . The connoisseurship of Yoshimune is governed by scarcity: his signed work is genuinely few, and the designated blades that survive are valued, in the words of the published record, as rare material for understanding the scope of his craftsmanship. A handful of his blades stand in the and tiers, with the Tsukubasan Jinja , an Important Cultural Property, the most famous of all and held as patrimony in the shrine that has long kept it. Where provenance is recorded it runs to institutional rather than private hands, and the published commentary names the Tsukubasan Jinja blade as the reference point against which his other works are read. For the collector this is a smith met rarely. A signed Yoshimune is not held in perpetuity in the way the school's most exalted designations are, and so it is not wholly beyond reach; but with so small a signed corpus, and most of it long settled, an example comes to market only from time to time, and an , signed in sound condition is a landmark when one appears.