While Mutsu Province was a place with good goldmine and breeding of good horses, the governor of it was on a mission of subduing some tribes of Ezo who did not come under the yoke of the Imperial Court, and subsuming other tribes of Ezo who once submitted (Fushu) but often seceded from the Imperial Court.
陸奥国は、金山や良馬に恵まれる一方、その国司は、朝廷の支配に属さない蝦夷を帰服させ、しばしば離反を繰り返した俘囚を服属させる任務を帯びていた。