When an Imperial force led by a supreme commander Yoshisada NITTA came to hunt down and kill Takauji ASHIKAGA, KO no Moroyasu tried to intercept the invasion in the Mikawa Province but was defeated.
その後、新田義貞を総大将とする朝廷の尊氏追討軍が攻めてきたとき、三河国でこれを迎撃し一旦は敗れる。