He was first appointed to be in charge of political affairs in the southern Oshu area as a loyal vassal of the Hojo clan, but when he received an order from Emperor Godaigo to attack the shogunate, he switched sides to the Imperial Court, invaded Kamakura in 1333 with Yoshisada NITTA, and destroyed the Kamakura bakufu (Japanese feudal government headed by a shogun).
はじめ北条氏の忠実な家臣として南奥州方面の政務を任されたが、後醍醐天皇から討幕の綸旨を受けると朝廷側に寝返って新田義貞と共に1333年に鎌倉に攻め入り、鎌倉幕府を滅ぼしてしまった。