Nanki Shigekuni signs his blades "made at Nanki"[[c:1]], and the published sources read that signature as biography. He was, they record, a smith originally of Yamato Province, a later offshoot of the Tegai group; in the Keicho era he entered the service of Tokugawa Ieyasu and forged at Sunpu, and in Genna 5 (1619) he moved in attendance upon Tokugawa Yorinobu when that lord was enfeoffed at Wakayama in Kii. His common name was Kuro-saburo, and one signature reads from the Monju temple of Mt. Meiko in Kishu, Monju Kuro-saburo Shigekuni, tying the line back to its Yamato Monju root. The published commentary does not flatten this descent into one manner. "His workmanship divides broadly into two"[[c:2]], it says, and names the two blade after blade: a Soshu-revival midareba made in private admiration of the upper Soshu masters, Go Yoshihiro above all, and the hereditary Yamato-Tegai suguha he carried as "his house art"[[c:3]], which the sources say "calls up Kanenaga"[[c:4]].
The first of the two manners is the one the NBTHK names as his typical and outstanding work. Over a flowing itame that mixes mokume and stands somewhat into a hada that lifts, the ji-nie sits thick and the chikei enters frequently, the steel clear. Upon that jigane he forges a shallow notare or small notare, mixing in gunome and at times a pointed togari character, widening the temper distinctly from above the monouchi; the nioi is deep, the nie thick and at times breaking up, and across the whole of it the kinsuji and sunagashi run freely, the nioiguchi bright and clear. The boshi runs sugu and turns in a small maru or yakizume, swept with hakikake. Among the Tokugawa-house smiths who set out in these years to revive the Soshu manner, his is the most active edge: the kinsuji and sunagashi that cover his blades run heavier than in any of his fellows, and it is exactly this clear bright character of ji and ha that the published sources single out, "the bright clarity of ji and ha is in particular his true province"[[c:5]]. On one Juyo wakizashi the commentary notes the kinsuji turning in spirals through the edge, a tell it calls a recurring feature of his Soshu work.
In either manner the jigane is one flowing itame, the ji-nie thick and the chikei well entered, the steel clear; the published record returns to this jihada as the constant beneath both his hands. It is a standing, lifting grain, not a fine close ko-itame, and it carries flowing nagare-hada more heavily than anything else he makes, the genetic Yamato trait that persists through both manners. The suguha-side blades show the inheritance plainly: a suguha-cho, at times chu-suguha or hiro-suguha, with small gunome mixing above the monouchi and the habuchi fraying into hotsure, kuichigai-ba, nijuba and yubashiri, the boshi ending yakizume or sugu and swept with hakikake. The masame-lean grain and the yakizume boshi are the marks of the Tegai descent, near his ancestor Kanenaga and all but absent in the Echizen and Horikawa smiths who revived Soshu without that Yamato blood.
The scholarship reads beyond the two manners to a third, which is where Shigekuni becomes himself. Taking a Soshu-den base and adding the Yamato-den, the commentary records, he established on that a manner of his own; the finest of these the NBTHK calls his "hakubi"[[c:6]], the high point, singling out the excellence of the jigane and the bright clarity of ji and ha. The Soshu side it elsewhere calls a Go-utsushi, a copy in the manner of Go, "what is called a Go-utsushi"[[c:7]], a vigorous make whose jigane too is clear and superb. Almost all of his blades are signed, in two registers, the long signature on the Soshu pieces and a two-character Shigekuni cut with a fine chisel, the latter rare on first-generation work; the NBTHK lumps the later Nanki generations under one attribution, marking the explicit shodai pieces where it can. On one wakizashi whose midare mixes gunome and yahazu-like elements the commentary catches "a hint of the Monju manner"[[c:8]] and reads in it "a forerunner of the hamon of the second generation and after"[[c:9]], the line opening toward the Kishu Shinto that descends from him.
The sources draw his distinction by his own traits rather than by what his models lack. Against the Soshu masters he admired, the bright, heavily nie-laden ji and ha and the freely running kinsuji and sunagashi are read as his own register, vigorous and clear; one early short sword the commentary calls the finest jigane of this smith, the ha bright and the activity abundant. Against the Yamato of his descent the flowing nagare-hada, the masame-lean grain, the kuichigai-ba and the yakizume boshi declare the Tegai blood that surfaces in even his Soshu blades, where the wide high shinogi and the swept boshi betray, the sources say, his native Yamato temperament. Looking the other way, the NBTHK reads in his Soshu work, where the boshi is burned across the yokote and turns round, bright in ji and ha, a manner that "runs in one vein toward Kotetsu"[[c:10]], and supposes that Kotetsu drew upon this very class of his work; the resemblance, traced to a master of the next generation, closes his lineage forward as Go and Kanenaga close it back.
Fujishiro grades him Sai-jo saku, and the weight of designation behind his name sits high among Shinto smiths: one of his blades is an Important Cultural Property, with six in the Tokubetsu Juyo tier and a further forty-four at Juyo, some fifty in the Tokubetsu Juyo and Juyo ranks together, and the official record holds his work as wholly signed, fifty-nine pieces, none mumei. The provenance recorded against his blades runs back to the house he served: examples descended in the Kishu Tokugawa family at Wakayama, and the Tokugawa Ieyasu and Tokugawa Yorinobu under whom he forged stand in the histories of his swords, with the Imperial Family among later holders. Several dated Genna 8 (1622) wakizashi survive bearing the possessor marks of Yorinobu's senior retainers, one made to the order of Kageyama Tosa-no-kami Munenobu, an elder of the Kishu domain, another carrying the mark of Tsuzuki Toichi, "a senior retainer of Yorinobu since the Mikawa days"[[c:11]]. The published sources observe that his Soshu blades, "for some reason, are for the most part shortened"[[c:12]], so that an ubu nakago among them is rare and counted a point of value. A signed Shigekuni is not among the unobtainable names; an example reaches the market from time to time, more often a wakizashi than a katana, while most of what survives is held in old daimyo and private collections, a Kishu Shinto landmark when one appears.
