Kanro Toshinaga signed himself Goshu Kanro Toshinaga of Takagi, and one tanto raised to Tokubetsu Juyo carries that full inscription below the peg-hole. He worked at Kanro in Takagi, in Omi Province, from the close of the Kamakura period into the Nanbokucho. From old times he has been transmitted as a pupil of Takagi Sadamune of the same province, and the published sources repeat the tradition without taking it at face value. Examining his extant signed work, they conclude that "rather than as a pupil, he should be regarded as a swordsmith of the same period"[[c:1]]. His signed pieces are few, tanto above all, with a dated ken and a rare tachi, so he is a name known through a thin but consistent body of work.
That body is read first in the forging and the point. Over an itame that flows and takes in masame, with ji-nie thick and chikei entering, he tempers a shallow notare kept low and quiet. Into the habuchi run hotsure, kuichigai-ba and nijuba, the edge breaking up in nie, with sunagashi and kinsuji drawn through it and yubashiri gathering toward the upper half. The boshi turns in a small round and is swept with hakikake at the point. The published sources name the masame in the steel, the frayed and doubled edge and the swept boshi as the marks of his signed work, and on them rest the reading that "he is regarded as a swordsmith of Yamato character"[[c:2]].
The jigane holds steady across his work. The itame mixes at times with mokume and o-itame, the grain standing a little and flowing, ji-nie thick and chikei frequent. On the wider mumei katana the steel opens into a flowing itame with passages of large grain, and the nioiguchi is described as bright and clear. Over so active a jigane the temper stays restrained, a low notare base into which gunome and a pointed tendency are mixed, the interest carried in the nie working of the edge rather than in the height of the pattern. Of one signed tanto the published commentary notes that the yubashiri, kuichigai-ba and nijuba in the upper half and the swept boshi "show the characteristics of Toshinaga well"[[c:3]].
His record divides in two. The first face is the signed tanto, several of them ubu and so preserving his own work untouched, in katakiri-ha or hira-zukuri with mitsu-mune, on which he occasionally carves bonji with a suken and goma-bashi. Within this group stand his two Important Cultural Properties, a hira-zukuri tanto and a double-edged ken dated Enbun 5 (1360). The second face is the mumei work attributed to him: o-suriage katana, mostly wide in body and flowing in the jigane, carrying the same low notare and swept boshi at full length, and beside them unsigned katakiriba wakizashi and tanto, wide and elongated in the Nanbokucho manner. The published sources accept one such katana with the plain judgment that the traditional attribution can be upheld. Two others show how the attribution is reached against his neighbour. A katana in chu-suguha-cho with hotsure, its shallow notare boshi swept again and again, is "at first sight in the Takagi Sadamune manner, with a Yamato colouring added"[[c:4]], and an unsigned tanto that likewise first suggests Sadamune is settled by its masame-tinged forging, its sunagashi and kinsuji and its nijuba-like yubashiri; of both the sources conclude that "it is proper to judge it Kanro Toshinaga"[[c:5]].
What sets him apart is what the judges name in him. His is a nie-laden, Yamato-flavoured manner, the flowing masame and the swept hakikake boshi marking his steel and his point, and the same nie working ties him to the Sadamune circle of his day. The connection to Sadamune is read as one of period and shared taste rather than of master and pupil. One wide Nanbokucho wakizashi, intensely nie-laden, with kuichigai-ba and hotsure along the edge and kinsuji entering, the published sources call "truly a work brimming with martial spirit"[[c:6]], and an unsigned tanto they receive as "a fine piece that connects to the smith's signed works"[[c:7]].
For the collector he is a rare early name with a small and largely held record. Fujishiro grades him Jo saku. He has no National Treasures. His standing rests on two Important Cultural Properties, the hira-zukuri tanto and the dated Enbun ken, both heritage preserved outside the market, together with a single Tokubetsu Juyo tanto and eleven Juyo blades among tanto, katana and wakizashi. Of the holders on record, one tanto is preserved at the Kosetsu Museum of Art and another blade at the Tokyo National Museum, one piece carries Date family provenance, and the remaining whereabouts are unrecorded. Only the Tokubetsu Juyo and Juyo tier could ever change hands, and even those come to light rarely, his extant signed works being, as the published commentary repeats, exceedingly few. A signed Kanro Toshinaga is an uncommon thing for a private collector to encounter, and a documented one a notable addition.