The earliest dated work that survives under this smith's hand is a naginata inscribed Kan'ei 2, 1625, and the seven blades gathered here, all signed Izumi no Kami or Izumi no Kami Fujiwara Kaneshige, are the work of the shodai alone. The published sources place him directly after the shodai Yasutsugu and Hankei as the next Edo smith of consequence; tradition holds that he came from Echizen, where he had been a yanone-kaji, a maker of arrowheads, before going to Edo and turning to forging blades, an account the Kokon Kajibikō preserves. He is rated Jō-saku by Fujishiro, and by long tradition he is the teacher of Nagasone Kotetsu. The name carries a second smith after him, his pupil Kazusa no Suke, also Kazusa no Kami, Fujiwara Kaneshige, and the two were for centuries treated as a single man, the change of title explained as deference to his lord Tōdō Izumi no Kami. The published sources set that story aside: signed and age-stated works, among them a katana of Kanbun 6, 1666, show the younger smith was born in Kan'ei 3, 1626, while the elder already bears Kan'ei dates, so the two are different individuals, and this profile is the first generation only.

The published sources draw his range as two manners, and the distinction governs how his work is read. The first is a notare-based temper carrying linked gunome, with ashi entering well, the nioi deep and the nie laid thick, and in his fullest pieces fine kinsuji and sunagashi running through the band with patches of coarser ara-nie, the nioiguchi bright and clear. On a katana of this manner the published sources find the workmanship so close to Kotetsu that it recalls him at a glance, 「一見徹を髣髴させる作域」[[c:1]], and read in the hardened edge a sense of strength and spirit. The second manner is a suguha base, sometimes a wide straight temper bearing the faintest notare and sometimes a chū-suguha of almost no movement at all, the nioi deep and the ko-nie well gathered, with a slight yakikomi at the machi and a bright, clearly defined nioiguchi. The constant across both is that clarity of the nioiguchi, the saeru quality the published sources tie to his Kotetsu-like character and name as the mark of Kaneshige at his best.

The jigane beneath both manners is a ko-itame, closely and well forged, with fine ji-nie laid thickly and chikei entering, in places flowing into nagare-hada and tending slightly to stand, mokume mixed in here and there. It is the controlled urban steel of an Edo master, the faint standing of the grain keeping the surface alive without breaking it open. The bōshi runs straight to a ko-maru, the kaeri at times long, the point swept with hakikake. The sugata is the transitional form of the Kan'ei and Shōhō years, of standard mihaba with a markedly pronounced taper, a retained funbari, rather deep sori and a compact chū-kissaki, which the published sources read as the passage from Keichō shintō to Kanbun shintō form and offer as a point of appreciation of his shape. The nakago is ubu, finished with ō-sujikai file marks already carrying a kesho-like tendency the published sources read as an early prototype of the later ornamental kesho-yasuri, and the long signature is cut with a fine chisel in a distinctive reisho clerical script of seven characters.

The two manners are registers, not periods, and the published sources name which a given blade exemplifies. The wide-suguha katana of the 61st Jūyō session they call a typical example of the former, the notare-gunome hand, its broad straight band mixed with notare and ko-gunome conveying an overflowing vigor; the deep-nioi suguha of the 43rd session they call a typical example of the latter, where the nioi runs especially deep and the nioiguchi becomes vividly clear. A third register is form rather than temper: his work is almost wholly shinogi-zukuri katana and wakizashi with tantō unseen, so that the broad, sun-nobi hira-zukuri wakizashi of the 31st session is a rare construction in which, the published sources note, its ko-notare mixed with gunome and bright nioiguchi show his true forte. Even within the notare-gunome manner there are blades of an entirely pure straight temper, 「純然たる直刃」, as the published sources remark of a Yamano cutting-test katana, so that the two hands shade into one another rather than dividing his career.

What sets him apart is best stated from his own grounded features. His tell is the pairing of a deep nioi with a bright, clear nioiguchi, carried equally over the calm wide suguha and the more active notare-gunome, and beneath it the densely ji-nie-laden ko-itame with its fine chikei and slight standing of the grain. The published sources frame his place in the school through Kotetsu at every turn: he is by tradition the teacher, his ji and ha deep in nioi and clear in the Kotetsu manner, and a katana of his is judged to recall Kotetsu at a glance. The line he founded ran on past him, his pupil Kazusa no Suke carrying it into the Kanbun years and perfecting the juzu-ba, the rosary-bead temper for which the second generation is best known and which the published sources hold could be mistaken for Kotetsu, so that the shodai's restrained two manners stand at the head of a school whose later fame rests on a temper he himself did not work. Recent study has gone to sorting the two hands apart, by which the elder's seven blades here are now read as the first generation's alone.

Kaneshige is among the leading Edo shintō names, and the shodai's reputation is inseparable from the cutting-tests that ride on his blades. Two of the seven here carry the gold-inlaid setsudan-mei of Yamano Kanjūrō, the name the great tester Kaemon used before the Shōhō era, recording a mitsu-dō three-body cut felled in two strokes and the inscription 「前代未聞剣 山野勘十郎切之」[[c:2]], an unprecedented sharpness cut by Yamano Kanjūrō, a provenance as much as an honor. On record under his name stand seven blades at the Jūyō rank and no higher designation, almost all shinogi-zukuri katana and wakizashi, with no National Treasure or Important Cultural Property among them and no recorded daimyō provenance, which is to say that what survives of him is the designated Jūyō blade rather than the museum-held icon. These are held mostly in long-standing private collections and come to market only from time to time, a signed Kaneshige bearing one of the famous Yamano cutting-test inscriptions the example most sought. He is not beyond the reach of a patient collector, but a piece of his, and above all one carrying the Yamano inlay, is a landmark when it appears.

The earliest dated work that survives under this smith's hand is a naginata inscribed Kan'ei 2, 1625, and the seven blades gathered here, all signed Izumi no Kami or Izumi no Kami Fujiwara Kaneshige, are the work of the shodai alone. The published sources place him directly after the shodai Yasutsugu and Hankei as the next Edo smith of consequence; tradition holds that he came from Echizen, where he had been a yanone-kaji, a maker of arrowheads, before going to Edo and turning to forging blades, an account the Kokon Kajibikō preserves. He is rated Jō-saku by Fujishiro, and by long tradition he is the teacher of Nagasone Kotetsu. The name carries a second smith after him, his pupil Kazusa no Suke, also Kazusa no Kami, Fujiwara Kaneshige, and the two were for centuries treated as a single man, the change of title explained as deference to his lord Tōdō Izumi no Kami. The published sources set that story aside: signed and age-stated works, among them a katana of Kanbun 6, 1666, show the younger smith was born in Kan'ei 3, 1626, while the elder already bears Kan'ei dates, so the two are different individuals, and this profile is the first generation only.

The published sources draw his range as two manners, and the distinction governs how his work is read. The first is a notare-based temper carrying linked gunome, with ashi entering well, the nioi deep and the nie laid thick, and in his fullest pieces fine kinsuji and sunagashi running through the band with patches of coarser ara-nie, the nioiguchi bright and clear. On a katana of this manner the published sources find the workmanship so close to Kotetsu that it recalls him at a glance, 「一見徹を髣髴させる作域」[[c:1]], and read in the hardened edge a sense of strength and spirit. The second manner is a suguha base, sometimes a wide straight temper bearing the faintest notare and sometimes a chū-suguha of almost no movement at all, the nioi deep and the ko-nie well gathered, with a slight yakikomi at the machi and a bright, clearly defined nioiguchi. The constant across both is that clarity of the nioiguchi, the saeru quality the published sources tie to his Kotetsu-like character and name as the mark of Kaneshige at his best.

The jigane beneath both manners is a ko-itame, closely and well forged, with fine ji-nie laid thickly and chikei entering, in places flowing into nagare-hada and tending slightly to stand, mokume mixed in here and there. It is the controlled urban steel of an Edo master, the faint standing of the grain keeping the surface alive without breaking it open. The bōshi runs straight to a ko-maru, the kaeri at times long, the point swept with hakikake. The sugata is the transitional form of the Kan'ei and Shōhō years, of standard mihaba with a markedly pronounced taper, a retained funbari, rather deep sori and a compact chū-kissaki, which the published sources read as the passage from Keichō shintō to Kanbun shintō form and offer as a point of appreciation of his shape. The nakago is ubu, finished with ō-sujikai file marks already carrying a kesho-like tendency the published sources read as an early prototype of the later ornamental kesho-yasuri, and the long signature is cut with a fine chisel in a distinctive reisho clerical script of seven characters.

The two manners are registers, not periods, and the published sources name which a given blade exemplifies. The wide-suguha katana of the 61st Jūyō session they call a typical example of the former, the notare-gunome hand, its broad straight band mixed with notare and ko-gunome conveying an overflowing vigor; the deep-nioi suguha of the 43rd session they call a typical example of the latter, where the nioi runs especially deep and the nioiguchi becomes vividly clear. A third register is form rather than temper: his work is almost wholly shinogi-zukuri katana and wakizashi with tantō unseen, so that the broad, sun-nobi hira-zukuri wakizashi of the 31st session is a rare construction in which, the published sources note, its ko-notare mixed with gunome and bright nioiguchi show his true forte. Even within the notare-gunome manner there are blades of an entirely pure straight temper, 「純然たる直刃」, as the published sources remark of a Yamano cutting-test katana, so that the two hands shade into one another rather than dividing his career.

What sets him apart is best stated from his own grounded features. His tell is the pairing of a deep nioi with a bright, clear nioiguchi, carried equally over the calm wide suguha and the more active notare-gunome, and beneath it the densely ji-nie-laden ko-itame with its fine chikei and slight standing of the grain. The published sources frame his place in the school through Kotetsu at every turn: he is by tradition the teacher, his ji and ha deep in nioi and clear in the Kotetsu manner, and a katana of his is judged to recall Kotetsu at a glance. The line he founded ran on past him, his pupil Kazusa no Suke carrying it into the Kanbun years and perfecting the juzu-ba, the rosary-bead temper for which the second generation is best known and which the published sources hold could be mistaken for Kotetsu, so that the shodai's restrained two manners stand at the head of a school whose later fame rests on a temper he himself did not work. Recent study has gone to sorting the two hands apart, by which the elder's seven blades here are now read as the first generation's alone.

Kaneshige is among the leading Edo shintō names, and the shodai's reputation is inseparable from the cutting-tests that ride on his blades. Two of the seven here carry the gold-inlaid setsudan-mei of Yamano Kanjūrō, the name the great tester Kaemon used before the Shōhō era, recording a mitsu-dō three-body cut felled in two strokes and the inscription 「前代未聞剣 山野勘十郎切之」[[c:2]], an unprecedented sharpness cut by Yamano Kanjūrō, a provenance as much as an honor. On record under his name stand seven blades at the Jūyō rank and no higher designation, almost all shinogi-zukuri katana and wakizashi, with no National Treasure or Important Cultural Property among them and no recorded daimyō provenance, which is to say that what survives of him is the designated Jūyō blade rather than the museum-held icon. These are held mostly in long-standing private collections and come to market only from time to time, a signed Kaneshige bearing one of the famous Yamano cutting-test inscriptions the example most sought. He is not beyond the reach of a patient collector, but a piece of his, and above all one carrying the Yamano inlay, is a landmark when it appears.