Tametsugu signed his blades Noshu-ju Fujiwara Tametsugu, and that inscription is the key to him. He is transmitted as a pupil of Go Norishige of Gofuku-go in , in some accounts a son of Go Yoshihiro, who carried the tradition out of the Hokurikudo and settled in . The published sources are careful with the link: among his extant works there are signatures naming both and , the published commentary noting that "there are inscriptions for both and " (越前と美濃の両方の銘文がある), while no example at all reads as resident in , the judges observing that "there is none signed -ju" (越中住ときったものはない). Because his dated pieces fall in the Joji and years of the later , two generations below Norishige's late- work, the swordbooks treat the Norishige discipleship as a manner received across a generation rather than a bond made at one forge, and find a direct link to Norishige, or to Yoshihiro, hard to sustain on chronology. He is best understood as the tradition carried north and inland, a Norishige hand resettled among the smiths of .
His characteristic manner is the one the judges name outright: a Norishige-style forging crossed with a temper. The published commentary states it plainly, that his work shows "a Norishige-style forging on which is tempered a -style and pointed , displaying a manner of its own" (則重風の鍛に美濃風の互の目尖り刃を焼いて一種の作風を示している). Over a standing he sets a mixed with into which the pointed of are folded, the strong and deep, and above all the run with a frequency that is his signature, drawn out long with within them. The does not blaze; it tends to subside, a quiet, restrained line, and the steel beneath it darkens. This combination, the wet Norishige given the sharp tooth and laid over a dark, -laden , is what a Tametsugu reads as on sight.
The is the constant. It is , frequently mixed with and large grain and flowing toward in places, the grain standing and at times opening, with thick and entering, and a steel of distinctly northern cast that darkens in tone. The published sources give as the common thread of his authenticated work an "that stands and darkens" (板目が肌立って黒ずみ), a -based temper whose subsides, and, as a negative tell, the fact that "there is no " (直刃はない) among the mainstream pieces. Over that the is most often a shallow carrying and , with and , and at the edge on the more active blades; the runs with frequent , turning in a or, on the many shortened , finishing in a sweep.
His record divides cleanly into two registers. The great body of it is the , unsigned attributed to him from style, broad blades with extended or large , on which the Norishige character is clearest. Against these stand the rare signed and dated pieces, exceedingly few, headed by an -dated that is a prewar Bijutsuhin, with a dated 7 (1374) and an cut Fujiwara Tametsugu . The published sources draw the contrast within his own work, noting that the flavor runs the stronger in the signed pieces while the Norishige manner shows more clearly in the attributions, and adding the candid judgment that the signed work can run somewhat coarse while "among the unsigned attributions there are, on the contrary, examples of quite good workmanship" (無銘極めのものには、なかなかよい出来のものがあり).
What sets him apart is read off his own blades, not borrowed from his master. His is the larger, more billowing , and the published commentary distinguishes him from the other hands by it directly, holding that his work "differs in manner from and Kaneshige" (志津、金重とは異っている). Beside Norishige himself the difference is one of degree and clarity: his does not stand as strongly and his are the fewer, the judges remarking on one blade that "the are less conspicuous than in his master Norishige" (師則重程地景が目立たない), and his steel darkens where the masters' is bright. The breadth of his manner reaches occasionally into other idioms, one shortened judged "workmanship in the Yamato Shikkake manner" (大和尻懸風の出来), a reminder that the provincial - he practiced absorbed more than a single line.
For the collector Tametsugu is a name encountered almost entirely through attribution. He has no National Treasures and no Important Cultural Properties; his record runs instead through the prewar Bijutsuhin and a long roll of blades across many sessions, the signed and dated pieces, the documentary core of the name, being the rarest of all. The published sources hold those few signed works to be of exceptionally high value precisely because so little survives, and longer signed examples are scarcer still. Owner records are thin: a pair of his blades is preserved at Atsuta Jingu, the passed through the prewar collection of Akaboshi Tetsuma, and most current whereabouts go unrecorded. The attributed to him do reach the market from time to time, a -Tametsugu appearing among - blades with some regularity, but a signed and dated Noshu-ju Fujiwara Tametsugu is a different order of thing, the document that fixes the name, and a privately held example is among the more uncommon encounters in the field. One such the published commentary calls outright "a quintessential example of Tametsugu's work" (為継の典型的な一刀), which is the best a collector can realistically hope to meet.