(初代信国) represents a distinguished lineage among the Kyoto smiths, flourishing from the period through the era. From old times he has been said to have been a disciple of Sadamune, and his period was traditionally transmitted as the Kenmu era (1334-1338). However, as the consistently observes, "among extant works there are no dated examples from Kenmu or nearby years, nor are there works that can convincingly be appraised as reaching that far back in time." Because the style of the earliest surviving blades--those dated Enbun and Joji--"connects directly with Sadamune," the prevailing view today recognizes the Enbun-Joji smith as the first generation. According to transmitted documents, he is recorded as the son or grandson of Ryokyunobu, a son of Ryokai, placing him within the school heritage of Yamashiro Province.
's forging characteristically shows mixed with and flowing , with the grain tending toward near the edge--a feature that accords with his lineage. Fine adheres thickly, enters well, and vivid stands out in his best works, producing a that is "bright and clear." His displays two principal modes: a dignified "that strictly preserves the tradition of Kyo-mono," and a mixed with in which the is deep, forms thickly, and vigorous activities such as , , , and emerge. The is repeatedly described as "bright and clear" (). His is typically with a slightly pointed tendency, often showing . The notes that both working modes--the ornate and the quieter --represent an inheritance from Sadamune, "who produced both modes," and that "successfully inherited his teacher's tradition and was highly accomplished."
The further emphasize 's mastery of toshin (blade carvings). His signed tantoblade at "leaves nothing lacking in the expression of his characteristic features," with carvings that are "superb and in fine harmony with the blade." Carved motifs include , , , , and ; the (superimposed carving) technique is singled out as "a specialty for which this group is particularly noted." Signed works by the are few, conferring heightened documentary value on each authenticated example. The Enbun 3 (1358) dated designated -Bijutsuhin is "especially valuable as a documentary reference example," while a formerly bestowed by the shogunal house upon the Owari house in Koka 2 (1845) and a known by the go "Arao "--transmitted in the Geishu Asano family--attest to the enduring regard in which this master has been held. Later generations bearing the name, including the Oei-period Saemon no Jo and Shikibu no Jo, continued both the and -based idioms, yet it is the 's direct connection to Sadamune and mastery of the - that defines the lineage's highest achievement.