The Kongōbyōe school (Kongōbyōe-) flourished in Province during the period alongside the more celebrated lineage. Based in the Reizen district, the school takes its name from the artisan Kongōbyōe, though signed examples are exceedingly rare, with the earliest documented work being a by Sadamori dated Shōhei 25 (1370) and designated an Important Art Object. This blade's signature—"Chikushū Reizen Sadamori"—confirms the school's geographic center and provides a stylistic benchmark for attributions within the tradition.
Kongōbyōe blades exhibit a distinctive Yamato temperament (Yamato kishitsu) in both and , setting them apart from typical Kyūshū productions. The forging characteristically combines large with and prominent , creating surface texture that stands out conspicuously. The tends toward a dark, slightly blackish tone with frequent interwoven throughout. The is invariably a narrow or , occasionally tinged with shallow or small inflections. The displays a characteristic tight feeling () with well-adhering , while modest and create refined scenery spanning and . Near the cutting edge, often transitions to , and appears along the .
The school's output demonstrates what period connoisseurs termed "metal flavor" (kanamono), reflecting Kyūshū forging traditions while maintaining the refined sensibility of Yamato technique. Extant works attributed to Ko-Kongōbyōe typically survive as greatly shortened () blades with proportions—wide , shallow , and —presenting dignified, powerful forms despite their modified state. The combination of dark-toned densely filled with fine , tight , and restrained activity creates a sober yet engaging aesthetic that distinguishes the school within the broader tradition.