The son of Kitabatake Chikafusa, a senior Southern Court statesman, Akinobu took over the Southern Court's administration of Mutsu after his elder brother Akiie died young in battle. In 1340 he was sent from Yoshino to Oshu as Chinjufu Shogun and established a provincial government and garrison headquarters at Uzumine in Tamura district. In 1341 he built Tsukumobashi Castle as a base for advancing south, fortifying various sites against the Northern Court. In the winter of 1351, amid the confusion of the Kanno Disturbance, he briefly retook the Taga provincial headquarters, but it was recaptured by the Northern Court in early 1352, whereupon he again held out at Uzumine Castle bearing Prince Morinaga (Uzumine no Miya), grandson of Emperor Go-Daigo. In May 1353, Uzumine Castle fell to a full-scale assault by the Northern Court army under Kira Sadaie, and Akinobu and the prince fled toward Dewa. He led Southern Court resistance in Oshu for fourteen years.

An indomitable commander who, bearing the tragedy of his brother Akiie's death in battle, continued leading the outnumbered Southern Court forces in Oshu for fourteen years.

The strongholds he built across Oshu, including Uzumine and Tsukumobashi castles, survive today as historic sites — some nationally designated — tracing the Southern Court's administration of the region. He symbolizes the protracted nature of the Nanboku-cho conflict in Oshu.