It was the Hojo clan (mainly the Tokuso family), a Shikken (shogunal regent) who took the real control of the bakufu then; the Shogun of Kamakura bakufu was just nominal.
当時幕府の実権は執権の北条氏（中心は得宗家）が握っており、鎌倉将軍は名目的な存在に過ぎなかった。