Kanro Toshinaga signed himself Goshu Kanro Toshinaga of Takagi, and one raised to carries that full inscription below the peg-hole. He worked at Kanro in Takagi, in Omi Province, from the close of the period into the . 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". His signed pieces are few, above all, with a dated and a rare , 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 that flows and takes in , with thick and entering, he tempers a shallow kept low and quiet. Into the run , and , the edge breaking up in , with and drawn through it and gathering toward the upper half. The turns in a small round and is swept with at the point. The published sources name the in the steel, the frayed and doubled edge and the swept as the marks of his signed work, and on them rest the reading that "he is regarded as a swordsmith of Yamato character".
The holds steady across his work. The mixes at times with and , the grain standing a little and flowing, thick and frequent. On the wider the steel opens into a flowing with passages of large grain, and the is described as bright and clear. Over so active a the temper stays restrained, a low base into which and a pointed tendency are mixed, the interest carried in the working of the edge rather than in the height of the pattern. Of one signed the published commentary notes that the , and in the upper half and the swept "show the characteristics of Toshinaga well".
His record divides in two. The first face is the signed , several of them and so preserving his own work untouched, in katakiri- or with , on which he occasionally carves with a and goma-bashi. Within this group stand his two Important Cultural Properties, a and a double-edged dated Enbun 5 (1360). The second face is the work attributed to him: , mostly wide in body and flowing in the , carrying the same low and swept at full length, and beside them unsigned and , wide and elongated in the manner. The published sources accept one such with the plain judgment that the traditional attribution can be upheld. Two others show how the attribution is reached against his neighbour. A in -cho with , its shallow swept again and again, is "at first sight in the Takagi Sadamune manner, with a Yamato colouring added", and an unsigned that likewise first suggests Sadamune is settled by its -tinged forging, its and and its -like ; of both the sources conclude that "it is proper to judge it Kanro Toshinaga".
What sets him apart is what the judges name in him. His is a -laden, Yamato-flavoured manner, the flowing and the swept marking his steel and his point, and the same 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 , intensely -laden, with and along the edge and entering, the published sources call "truly a work brimming with martial spirit", and an unsigned they receive as "a fine piece that connects to the smith's signed works".
For the collector he is a rare early name with a small and largely held record. Fujishiro grades him Jo . He has no National Treasures. His standing rests on two Important Cultural Properties, the and the dated Enbun , both heritage preserved outside the market, together with a single and eleven blades among , and . Of the holders on record, one 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 and 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.