Izumi no Kami Fujiwara Kaneshige is the founder of the Kaneshige line, and the published sources place him precisely in the city's early : "the smith who appeared after Yasutsugu and Hankei was Izumi no Kami Kaneshige". By tradition he was an arrowhead smith who moved to and turned to forging swords. His dated record runs from 'ei to Meireki, in their words "the earliest date is 'ei 2, and the last reaches Meireki". He was long thought to be the man as Kazusa no Kaneshige, who was said to have changed his title out of deference to his lord Tōdō Izumi no Kami. Signed and age-stated works now show Kazusa no born in 'ei 3, and the published sources conclude that "Izumi no Kami and Kazusa no Kaneshige were clearly different men".
His work is almost entirely and : "his works are mostly and , and are not seen". The is that of the 'ei and Shōhō years, of ordinary width with clear taper, a retained and a compact chū-kissaki, which the published sources call "the transitional shape moving from Keichō shintō to Kanbunshintō"5. The jigane is a ko-itame, closely forged, at times flowing and standing somewhat, with ji-nie and chikei.
The published sources state that his temper is "broadly divided into two manners"6. The first is a notare base with gunome running linked through it and ashi entering, the nioi deep, nie thick, kinsuji and sunagashi running, the nioiguchi bright. One katana of this kind opens "with a yakidashi at the base"7 before the shallow notare, on a thick, full-bodied blade. The second is a deep-nioisuguha, often bearing a very shallow notare, with a bright and clear nioiguchi; of one such katana the sources write that its deep nioi, thick nie and brilliant nioiguchi are "the characteristic of this smith when he took up this kind of work"8. Some are a pure straight temper, "there are also pure suguha"9, on "a ko-itame with ji-nie, the nioiguchi bright and clear, an outstanding work"10. Others carry "a shallow notare, skilfully tempered"11, or a suguha whose "activity within the ha is lively"12, and on one katana "the nioiguchi is notably deep"13. The bōshi runs straight to a ko-maru, at times swept at the tip.
His nakago are themselves a point of study. The long signature is cut in a distinctive clerical hand, "the signature is in his own distinctive reisho"14, and in late work the characters grow smaller and the chisel finer. The file marks bear a kesho tendency that the published sources read as "not quite the decorative kesho-yasuri of later times, but to be seen as its prototype"15. A rare hira-zukuriwakizashi of broad, elongated form is called "one of few hira-zukuri examples and well made"16.
His blades are bound to the great Edo cutting testers. Many carry the gold-inlaid setsudan-mei of the Yamano family, and the published sources use them to date the work: a cut recorded under the name Kanjūrō shows a blade made "when Kaemon was still called Kanjūrō, a work of up to about Shōhō 2 or 3"17. He is by long tradition the teacher of Nagasone Kotetsu, and his successor Kazusa no Suke, his son or pupil, carried the linked gunome into the juzu-ba for which that later generation is known.
Fujishiro grades him Jō saku, and fourteen designated works are on record, all in the Jūyō tier. Of the finest the published sources write that the work is "a blade in which the temper brims with spirit and conveys power"18. For a collector a signed katana of his, often with a Yamano cutting test on the tang, is a realistic if occasional encounter, and a dated piece or a hira-zukuriwakizashi is rare.
Historical importance
Where Kaneshige stands among comparable artisans: across all of nihontō, and within tradition, era, and period. The tiers (Foremost · Leading · Major · Notable) weigh official designations from the NBTHK and Japan's Agency for Cultural Affairs, together with historical honors of lasting repute such as the Sansaku and Meibutsu-chō.