Oku Motohira was a retainer of the Satsuma Domain and the legitimate son of Oku Motonao. Born in Enkyo 1 (1744) with the common name Kozaemon, his swordmaking is seen from the Meiwa era onward. At first he signed such inscriptions as "Satsuyoshi Motohira" and "Satsuhanshin Oku Motohira," but after receiving the court title Yamato no Kami in Kansei 1 (1789) -- at the time as his contemporary Hoki no Kami Masayuki -- he frequently signed "Oku Yamato no Kami Taira Ason Motohira." Together with Masayuki, he stood as the foremost figure in the Satsuma shinshin-to milieu. He continued producing many swords as a leading smith until his death in Bunsei 9 (1826) at the age of eighty-three. A collaborative work with his younger brother Motoyasu also survives.
Motohira's characteristic manner is a - style featuring mixed with and , with deep accompanied by vigorously adhering and , and conspicuous thick, long and . His forging shows compact with thick and plentiful , at times displaying -maji. The frequently shows vigorous , in the finest examples producing a flame-like () appearance. He also produced accomplished -based works in which shallow and are mixed into the foundation, displaying the deep and fine that define his oeuvre.
Motohira's boldly hardened edges convey a forceful sense of impact and strength. Among his works, those forged for the retainer Motooki to transmit the techniques of forging and tempering survive as precious material for understanding the master-student relationship within the Satsuma tradition. His blades, often of notably bold and magnificent form, represent the apex of late -period Satsuma swordsmithing.