Partially because the clan was urged by the Shogun Yoshiaki ASHIKAGA, who had fled to Tomo, the Mori clan broke diplomatic relations with the Oda clan in 1576.
天正4年（1576年）、鞆に落ち延びてきた将軍足利義昭の強い誘いもあり、毛利氏は織田氏と断交した。