In August of the same year, the Southern Court including Tadakuni invaded Izaku to fight against the Northern Court let by Hisanaga SHIMAZU of the Izaku family, but it was indecisive.
同年7月、忠国ら南朝方は伊作へ侵攻、伊作家島津久長の率いる北朝(日本)方と交戦するも勝敗は決しなかった。