However, when the generation of shugo, Masatsune KYOGOKU started, Masatsune gradually deepened confrontation against shugodai (the deputy of shugo), Tsunehisa AMAGO and, when Masatsune expelled Tsunehisa, Tsunehisa AMAGO made a surprise attack on the employer's household the following year, usurped the territory and the authority from his master, and became shugo of Izumo.
しかし、守護京極政経の代に入ると、政経は守護代尼子経久と次第に対立を深め、政経が経久を追放すると、その翌年には尼子経久が奇襲を持って主家を攻め、主君より領土と実権を奪い、出雲守護となった。