Yoritomo concluded that he should accept the post of 'Asa dai-shogun' (the great general of the country) once, to vindicate honor of his father who was killed as Gyakushin (rebellious subject).
そして、逆臣として討たれた父の汚名を雪ぐ意味で一旦は「朝大将軍」（国の大将軍）を受けた方が良いと判断した。