Tsunemitsu is a swordsmith of the Masatsune line, working at the close of the and the opening of the period. The published sources transmit him as the son, or else a disciple, of Masatsune, and read his work as belonging unmistakably to that house: of the formerly in the Daishōji Maeda family they write that it 'displays workmanship in both and shared with Masatsune' (地刃共に正恒に共通する作風を示しており), enough to accept the maker as one of that line. His surviving record is small, a handful of signed and a single shortened drawn to him on workmanship alone, and the commentary returns each time to the point, that signed works by his hand are 'comparatively few, in contrast to Masatsune' (この工の在銘作は、正恒と相反して少なく). He is one of the quiet old- hands standing at the threshold before the Fukuoka would flower in the mid-.
His hand is a single manner read through a spread of quality rather than two separate registers. The temper that recurs across his signed blades is a -based into which and are mixed, with and entering, the tending slightly toward tightness, adhering well, and and running frequently through it. It is a shallow, small irregular line, calm by the standard of later , and it is by this temper above all that the school knows him: on the Daishōji Maeda the published sources note that 'in both and the blade calls Masatsune to mind' (この太刀は刃文も帽子も正恒をおもわせるものがあって), the signature clear and the nearly shape valuable in itself. The runs straight into a small round, the piece finishing instead in a larger , and on three of the a is carved through, terminating in .
Beneath that temper the is a well-packed , standing a little in places, with and a faint rising in the calmer pieces. On his best blades the reflection clears into a true over a slightly standing mixed with a little , entering, the old- the judges name among the principal points of his work. The shape is the bearing of his period throughout, slender, with a clear taper from base to point, a high with and a small , the settling toward the tip.
His most decorative surviving pieces open the manner toward flamboyance without leaving it. On the of the sixty-second session the temper rises high at the in a -like fashion, then proceeds in a mixing and , the showing , fine and intermixing, and running, while a clear stands in the ; the published sources call it a blade in which 'the points of interest of old work are well displayed' (古備前物の見どころがよく表示されている). On the of the thirty-eighth session the mixes with and becomes a shallow toward the , the tightening and the predominating, named by the judges as one characteristic style of this smith. The signed work is the body of his record, and cut with a bold two-character ; the one shortened , wide-bodied and in the , was placed within the line on its and despite the loss of its signature.
What separates Tsunemitsu within old is exactly what the judges name in placing him. His calm -based , his bright on the finest pieces, and his and held in common with Masatsune mark him as that smith's nearest follower, while his quiet line and his comparatively few signatures set him apart from the more prolific master and, looking forward, from the flamboyant of the Fukuoka that the mid- would bring. One commentary, examining the most representative of his surviving , calls its signature 'the most typical example' of his hand, the touchstone by which the rest are read.
For the collector he is a rare early name with a small but high designated record. Fujishiro assigns him no grade, and he has no National Treasures; his survival runs instead through one signed designated an Important Cultural Property, one raised to , four at , and two prewar Jūyō Bijutsuhin, almost all of them signed. His blades are heritage carried down in named houses and a public collection rather than swords that circulate: the and one descended through the Daishōji Maeda family of , the latter accompanied by a Kōjō appraising it at fifteen gold coins; the two Jūyō Bijutsuhin passed through Tachibana Kantoku of Fukuoka; and one of his blades is now held at the Seikadō Bunko. The Important Cultural Property is patrimony that does not come to market, and the handful in the and tiers reach it only rarely, since the published sources call an , signed example 'few in number, of high value as reference material' (数少ない同工の生ぶの有銘作として資料的に貴重であり). A signed Tsunemitsu in private hands is among the rarer things a collector of early could hope to encounter, and one appears, when it does, only with patience.