In 1333 when Emperor Godaigo escaped from exile in the Oki Islands and raised an army to overthrow the Kamakura bakufu, Tadayoshi and his elder brother Takauji allied with him and participated in the attack on Rokuhara Tandai (an administrative and judicial agency in Rokuhara, Kyoto).
1333年（元弘3年/正慶2年）、後醍醐天皇が配流先の隠岐島を脱出して鎌倉幕府打倒の兵を挙げると、兄の尊氏とともにこれに味方し六波羅探題攻めに参加する。