When Akiie KITABATAKE won the strong trust of Emperor Godaigo and was permitted to live in Taga-jo Castle due to his performance on the battlefield, Munehiro was appointed to district magistrate and also the ruler of the Oshu area.
その功績により、後醍醐天皇から厚い信任を受けて北畠顕家が多賀城に入ると、諸郡奉行に任じられて共に奥州方面の統治を任されるに至った。