Sakyo no Munemitsu was the second son of Rokurozaemon no Jo Sukemitsu and the younger brother of Ukyo no Katsumitsu, both of the school in Province. He is counted among the representative swordsmiths of . In Chokyo 2 (1488), in response to an order from Shogun Ashikaga Yoshihisa, he went together with his elder brother Katsumitsu to the campaign encampment in Omi and there forged swords. It is also transmitted that he established temporary forges in various localities of and , and further that, as a subordinate of Akamatsu Masanori, he participated in warfare — circumstances by which his conspicuous activities are well known. His working period spans from the Bunmei era through the Eisho era, and because the name Munemitsu continued across a notably long production span, it is considered likely that the title was carried into a second generation, though a firm chronological boundary between the two remains difficult to establish. Collaborative works with his elder brother Katsumitsu, popularly called Sokatsu, are comparatively common and have long been especially treasured by connoisseurs; further joint works with his nephew Jirozaemon no Jo Katsumitsu are also recorded. Inscriptions from Kojima in and Kusakabe in document the itinerant forging stations where the brothers established their workshops during the Bunmei period.
With regard to workmanship, Munemitsu is widely esteemed for both and styles. His characteristically shows a dense tightly forged, with fine adhering thickly, entering, and standing out — sometimes tending toward in works. In the mode, for which he holds a particularly strong reputation as a highly skilled maker, the is rendered as a slender or broad mixed with , featuring and working actively, with a that tends toward tightness and to which adheres well. In the mode, the mixes open-based , , , , and a --like manner characteristic of ; the temper is broad with conspicuous undulations; appear here and there; and occur; and the is bright and clear. The typically shows turning back in , or in works runs straight with a rounded return. In comparison with Katsumitsu and related smiths, Munemitsu's temper patterns tend toward a more restrained, smaller-scale design. Powerful and splendid — including formal , , , , and inscriptions such as — frequently appear on both sides, executed by specialist engravers in a manner that vividly expresses the distinctive characteristics of .
Munemitsu's oeuvre constitutes essential source material for the study of late swordsmithing and the movements of the school during the turbulent Onin and post-Onin decades. The blades consistently present the typical construction of the period — standard , thick , , and short suited to one-handed nukiuchi — and his workmanship in both and is bright and clear, fully endowed with points of appreciation. Joint works bearing place-of-forging inscriptions from Kojima and Kusakabe in are particularly valuable as documentary evidence illuminating the brothers' itinerant activities, while dated inscriptions spanning Bunmei through Eisho provide a critical chronological framework for scholarship. The accompanying and provenance records — including mountings transmitted in the Date family and blades held in the Imperial Collection — further attest to the enduring esteem in which these works have been held.