Nearly every published designation text on Kuniyoshi cites the Narukitsune, the Crying Fox, a large bearing his long signature Sahyoe-no-jo Fujiwara Kuniyoshi, and newly judged blades are still read against its manner. Kuniyoshi is recorded as the son of Norikuni, by some accounts his pupil, and a grandson of Kunitomo, eldest of the six brothers of Yamashiro; his younger brother was Kunimitsu. Transmitted as either his son or his student is Toshiro Yoshimitsu, the celebrated master of the . A dated Koan 3 (1280) survives, and the sword drawings of the old books preserve dates of Kenji 4 (1278), Koan 6 (1283) and Koan 10 (1287); by these the published sources confirm the traditional sequence of the generations and fix him in the middle period.
The published record describes his manner in a settled formula: a finely kneaded rich in , beautiful in effect, and a in well-attached mixing and , the and together judged "a degree stronger than the works". Above everything stands the , the doubled line that runs conspicuously along the and is cited again and again as his greatest point. The Kaifunki already names it his habit: "as a habitual mannerism there is often , and silver often floats in the as in a cast object". At times the line trebles into sanjuba, often formed of strung along the edge, and on more than one blade it carries into the . and enter frequently, and fine work through the , and the is repeatedly described as bright and clear. The is typically straight with a refined turnback.
The carries the school's name. He forges a mixed with , kneaded extremely tight, over which sits dust-fine and thick with delicate , until the steel takes on the so-called , the pear-skin steel of the idiom. stands over it, at times with a faint -like tone mixed in. The Kokon Meizukushi praises the taste of his steel as a gleam deep in the color of the , "like the silver of a tenmoku bowl dusted with ash".
His certain signed number only two. One has long been an Important Cultural Property; the second surfaced only at its designation in 1997, a slender, elegant blade of high -zori with . A third, shortened, with a two-character low on the tang, was admitted at its designation as extremely close to those two. The are comparatively many and carry most of his signatures, the number several, and the Narukitsune stands apart as the single great . The shapes, stubby and wide like a kitchen knife, ordinary, slender and elongated, or wide and elongated, in or without curve, are called "remarkably diverse" and opposed to the uniformity of the school; like Yoshimitsu he often works the temper down over the , and or are carved on many. The unsigned blades are the more numerous, of wide and shallow wa-zori with the pulled in fashion, where the grows busier with and , and thick. On these the is the point on which the judges anchor the attribution, and one ayame-zukuri is judged to give the very impression of a Narukitsune enlarged. The are elegant, the point not flaring, often in with the , and "the of this maker often show strong ". The signature is normally the two characters Kuniyoshi, the chisel running from fine to ordinary to thick, a variety ascribed to difference of period.
On his relation to Yoshimitsu the published sources reason from the dates. Kuniyoshi has the Koan 3 and the dated drawings of the old books; Yoshimitsu has no dated work at all, extant or recorded. Both made few and excelled in of unusually varied shape, and from this the judges find it reasonable to see the two not as father and son but as master and pupil of comparatively small age difference. One text states plainly that together with Yoshimitsu of his school he produced many , both displaying superior technique. The appears on nearly half of his records, only occasionally in Yoshimitsu's, and never in those of his father Norikuni; the sanjuba is met in his work alone among them; and it is on his records that the texts name the outright.
Fujishiro rates him Sai-jo , and fifty-one designated works stand on record. There are no National Treasures among them, but seven blades are Important Cultural Properties, his long-known signed at their head, and five are prewar Bijutsuhin, one a formerly of the Aoyama viscount family of Sasayama. Eighteen blades hold the rank and twenty-one the , thirty-nine in the two tiers together. The provenance roll is in keeping. A signed with an of Koon descends in the Matsudaira house of Iyo Saijo, and a in the Reizei house of court poets; the two-character was owned by Okubo Ichio and passed to the Iwasaki house; a signed belongs to the Owari Tokugawa Reimeikai; and one signed , by its scabbard inscription, was presented by Todo Takamutsu at a birth celebration in the Tokugawa house. Of recorded whereabouts today, examples rest in the Tokugawa Art Museum, the Kyoto National Museum and the Hikone Castle Museum, with others in private hands. For the collector, Kuniyoshi is by measure not wholly beyond reach. The Important Cultural Properties are patrimony preserved outside the market, but the thirty-nine blades of the and tiers are where a private example is met, most of them whose attribution rests on the doubled line along the . Such a blade comes to market only rarely, and is an event when it does; a signed is rarer still, and a signed , of which two certain examples exist, is among the rarest encounters the school affords.