Mitsukane of Yamashiro, active at the end of the period, is recorded as a pupil of Kunitoshi and, in the 's recurring phrase, "a smith apart within the school". Tradition gives him a chapter as well: he is said to have gone to and studied under Nagamitsu, and on the order of events the published sources are precise, observing that "most transmitted records state that he first studied under Nagamitsu and afterwards entered the school of Kunitoshi". He lived and worked at Tozu in Omi, whence the name Tozu (戸津来), and by the legend the texts repeat in nearly every designation he withdrew to forge at the Konpon Chudo, the central hall of Enryaku- on Mt. Hiei, whence the name by which he is best known, Chudo (中堂来). He signed with the two characters Mitsukane alone, never crowning the signature with the character . About scarcity the record is emphatic: "examples encountered are extremely few; there are no , only ", and the signed work is confined to .
The build announces him before the steel does. His are with , somewhat elongated and often a little wide in the , with , and the published sources fix the construction in a standing formula, naming "the thick kasane and sturdy construction"4 together with a boshi "whose roundness is large and whose kaeri returns wide, deep and long"5 among the features to see. The oldest commentary in the corpus already treats both points as his habit, writing that "there is rather more variation within the ha than in his teacher Rai Kunitoshi, and the kaeri of the boshi is as a rule long"6. The hamon itself is a suguha in the manner of his teacher, though one designation adds that he "burns a suguha wider than Kunitoshi's"7. Into the quiet line mix ko-midare, a feeling of ko-choji or ko-gunome, and kuichigai-ba; ashi and yo enter, the nioi runs deep, ko-nie lies thickly, and kinsuji and fine sunagashi work through a nioiguchi that stays bright and clear.
The jigane is the declared tell, and the NBTHK states it almost verbatim across the later texts: the jigane of this smith "has as its special quality that the ji-nie is laid on exceptionally thickly so that it looks strong, and the loose, weak texture called Rai-hada is in general rare in him"8. The kitae is a finely packed ko-itame, mixing flowing hada toward the ura or along the edge and a touch of larger hada at the koshimoto; the ji-nie sits dust-fine and thick, a nie-utsuri rises, and the steel is bright. One designation widens the contrast to the whole school, finding that "the jigane is stronger and clearer than that of Rai Kunitoshi or Rai Kunimitsu"9 and naming that strength a point to see. The old kantei literature reached the same judgment in its own words: the NBTHK quotes the Edo text Nyote-hikisho (如手引抄) to the effect that, compared with Kunitoshi, the color of his ji is bluer and clear to the bottom, the nie fine and vivid, "like the nie of Awataguchi Yoshimitsu"10. Horimono appear on a few pieces, gomabashi paired with a stout koshi-hi, or a suken on the omote with bonji on the ura.
Against this suguha mainstream the texts set exactly one exception, rehearsed in nearly every designation: "there exists one single work that burns a midare-ba led by gunome, of a kind that underwrites the theory that he was Nagamitsu's pupil"11, the meibutsuMidare-Mitsukane12, an Important Cultural Property whose deki at first sight recalls Bizen. The oldest text in the corpus names the Bizen teacher as Kagemitsu rather than Nagamitsu, judging works of this group "almost the image of Kagemitsu, though stronger than Kagemitsu in the nie of ji and ha"; the later texts settle on Nagamitsu. The surviving record divides as well by signature. The signed pieces are slender nijimeitanto in a fine suguha, while the broad wide-suguha examples are the larger unsigned works, among them a sunnobiwakizashi carrying not a signature but a shu-mei, the Hon'ami house's red-lacquer attribution reading Mitsukane with Hon'a and a kao, whose deki the NBTHK judges "an accomplishment surpassing even the signed Mitsukane"13; the document of its old scabbard records that the fifth shogun Tsunayoshi presented it in Enpo 8 (1680) to mark his son Tokumatsu's move to the Nishinomaru of Edo castle.
In kantei he stands as the strong pole of the Rai school. Where the school's quiet suguha can ride on a soft, loose jigane, his carries nie laid on thickly over a tight ko-itame; where his teacher's tanto are slender, his run thicker in the kasane and a little longer in the body; the suguha is wider, the movement within it greater, and the boshi rounder, its kaeri deeper and longer. The literature reaches past his own school for the comparison, likening the fineness and vividness of his nie upward to Awataguchi Yoshimitsu rather than across to his Rai fellows. The texts name no pupils and no continuing line, and his manner closes with him; what remains is a small, coherent body of tanto in which, as the published sources put it of the best examples, the typical manner of Chudo Rai Mitsukane is displayed to the letter.
Fifteen designated works stand on the official record: four Important Cultural Properties, among them the Midare-Mitsukane and a signed tanto transmitted in the Date family, three Tokubetsu Juyo, and eight Juyo, eleven blades in all in the Tokubetsu Juyo and Juyo tiers; five of the fifteen are signed, ten unsigned. The provenance recorded against them runs through the great houses of the Edo period. The meibutsu Kuwayama Mitsukane14, an ubumumeitanto listed in the Kyoho Meibutsu-cho, takes its name from Kuwayama Iga-no-kami Motoharu, passed to the third shogun Iemitsu, was granted by him to Maeda Toshitsune, and descended thereafter in the Maeda family; it stands today among his Tokubetsu Juyo. The shu-meiwakizashi descends from the Tokugawa main line. Of recorded whereabouts, his blades rest with the Tokyo National Museum, the Fukuyama Art Museum and the Kurokawa Research Institute, with one in private hands. The four Important Cultural Properties are patrimony, preserved where they are; the eleven blades of the Tokubetsu Juyo and Juyo tiers are what a collector could in principle encounter, and for a smith whose surviving examples the published sources themselves call extremely few, one reaching the market is a rare event.
Historical importance
Where Mitsukane 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.