Mototoki was the commissioner of the northern Rokuhara Tandai in 1302, although his name can't be identified in the members of Yoriai-shu around this time, and his father Tokikane HOJO's name appears in the birth article as a son of Naritoki HOJO, a younger brother of Nagatoki AKAHASHI, Mototoki's grandfather.
基時は1302年（乾元元年）当時六波羅探題北方で、この時期の寄合衆としては確認出来ないが、その祖父で赤橋長時の弟の北条業時の子として父北条時兼の出産記事がある。