Naotsugu is one of the foremost representative smiths of the school of Province, active from the close of the period into the early period. Sword-signature reference works place him as flourishing around the Karyaku era (1326--1329), and extant dated works range from as early as Gentoku through Shokei, Kenmu, Ryakuo, Jowa, and Kanno, establishing a documented career of remarkable breadth. He used the court titles Saemon no Jo and Sahyoe no Jo, and together with smiths such as Yoshitsugu he stands among the principal craftsmen of the school during this transitional era. The record a first generation active from the late through the Kenmu era and a second generation extending through Enbun, though the first generation --- signing " no junin Naotsugu" and occasionally appending his official titles --- remains the more celebrated figure. The lineage itself traces its renown to the early eleventh-century Sarugakki, which lists "the swords of " among the noted products of the provinces; smiths of the group subsequently emerged as heirs to this high reputation, centered in the lower basin of the Takahashi River.
Naotsugu's work is grounded in the -based idiom characteristic of late production, yet it is executed with a refinement and clarity that distinguish him within the school. His is typically a dense, tightly forged mixed with , often incorporating the -like texture and mottled patches that are hallmarks of the tradition; fine adheres abundantly, with delicate interwoven, and or stands out with varying degrees of clarity. Some works display a --- a crepe-like surface texture --- that is especially characteristic of the school. The is fundamentally , ranging from narrow to medium , mixed with , shallow , and angular or reverse-slanting elements; , , and enter, and the is consistently described as tight, bright, and clear, with adhering. The characteristically runs straight and turns back in , often with a pointed tendency. His frequently exhibits the furisode shape inherited from the tradition, with file marks and boldly chiseled, forceful long inscriptions cut with thick or fine chisels showing the effect of . Among -period works attributed to later generations, a florid - temper also appears, reflecting the school's stylistic evolution.
The assessments consistently characterize Naotsugu's production as demonstrating the manner of the school with particular clarity and superior workmanship. Both and are repeatedly described as --- sound and well-preserved --- and as bright and clear, with the tightly forged and finely woven singled out for special commendation. The is well maintained, lending his blades a firmly built, weighty impression. He is praised as producing "especially outstanding" and "especially distinguished" works that "fully demonstrate the stylistic character of this school in the period," and his signed, dated examples --- bearing official titles and era inscriptions from Gentoku through Kanno --- are valued as precious documentary material for the study of the tradition. It is further noted as a point deserving particular attention that Naotsugu occasionally cut his signature in orientation rather than , an uncommon practice within the school's works of this period.