Takanobu, who had entered into an alliance with the Mori clan of Aki, killed the lord of Shikano-jo Castle Toyonari YAMANA (the son of Nobumichi) in 1563 by poisoning him, and he defeated Toyokazu in the Battle of Yutokoroguchi during April of the same year.
1563年（永禄6年）、安芸の毛利氏と結んだ高信は鹿野城主・山名豊成（誠通の子）を毒殺、同年4月の湯所口の戦いで豊数を破った。