Echigo no Kami Kunitsugu was a disciple of Kunihiro, and one tradition holds that he was Kunihiro's nephew. The Kokon Kaji Biko records that he was "born in Obi in Province and resided at Ichijo in Joshu" and was "a maker of good workmanship." The Shokan Yoroku adds that "Masahiro and Kunitsugu appear to have been disciples who followed from to the capital region." He is regarded as the youngest among Kunihiro's disciples and is seen as, in effect, the mentor who guided fellow-school smiths Izumi no Kami Kunisada and Kawachi no Kami Kunisuke -- an inference drawn from the close resemblance of their early workmanship and signature mannerisms to Kunitsugu's own. A separate smith of the line, Daijo Kunitsugu, was among the outstanding students of Dewa Daijo Kunimichi, and it is conjectured that in Kunimichi's later years this Kunitsugu likely served in the capacity of producing (substitute forging) and (substitute signing). A further tradition connects the individual with the name Hokyo Kunitsugu Nyudo Jutetsu.
While many works are understood as aiming toward the manner of higher-ranked - masters such as and Sadamune, Kunitsugu is distinctive in presenting a style strongly imbued with character -- particularly suggesting an emulation of Izumi no Kami Kaneyuki and the late-Seki mode. His forging shows two broad types: one with prominent grain and a rough texture typical of works generally, and another with more tightly forged in dense . The characteristically begins with a , followed by mixed with , angular, and pointed elements. The tends to tighten and shows a (subdued) tendency, with adhering and fine running through. The forms a shallow , returning roundly and deeply, often with . of , , , and are frequently encountered.
His signature is invariably cut as the seven characters "Echigo no Kami Fujiwara Kunitsugu," and no dated works are known. The arrangement of the signature is slightly distorted, with characters gradually growing larger as they descend -- a point especially worth noting in his tang construction. Relative to the blade, the tang tends to be short, and within the group his chisel is described as the finest. Forms such as and are frequently encountered in his output, and blades in which "both and are (sound and well-preserved)" recur as a consistent note of praise. The has assessed individual works as "a masterpiece among Kunitsugu's oeuvre," and collectively his production demonstrates a smith whose individuality is fully expressed within the tradition.