Ietsugu belonged to the Aoe school of Bitchu Province, a lineage whose activity spanned from the mid-Kamakura period through the late Nanbokucho era. He is recorded in the Meikan as a son of Moritsugu, and his works are appraised across two distinct periods: a tachi bearing a tachi-style signature is attributed to the Naka-Aoe group of the middle to late Kamakura period, while dated works inscribed Enbun 2 (1357) and Shitoku 3 (1386) place him firmly in the Nanbokucho era. This range suggests either a long working life or, more likely, successive generations operating under the same name.

The Naka-Aoe tachi displays the school's hallmark qualities: a dense ko-itame-hada with ji-nie and utsuri standing out, paired with a suguha-cho temper where the nioiguchi tends toward tightness with abundant ko-ashi and adhering ko-nie. The NBTHK notes that "the characteristic features of this lineage are well expressed in both the jihada and the hamon." The later tachi dated Shitoku 3 is especially significant, as signed works of the Aoe school from this period are described as "extremely rare — not only those by Ietsugu, but in general." Despite workmanship the NBTHK candidly assesses as not rising to a high level, the piece is valued as "exceedingly precious as documentary material."

What emerges from the designated corpus is an artisan of considerable documentary importance to the study of the Aoe tradition. His tanto dated Enbun 2 differs in form from the large, elongated examples of contemporaries such as Tsuguyoshi and Tsugunao, making it "useful for research on the Aoe school." Across his surviving works, Ietsugu preserves the essential vocabulary of Bitchu craftsmanship while documenting the school's evolution through its final active centuries.