As ordered by Yoritomo, the engagement of a granddaughter of Yoshizumi MIURA to Yasutoki was determined simultaneously with his coming of age and, eight years later, Yasutoki welcomed Yoshimura MIURA's daughter (a nun, Yabe-zenni) as his wife on September 17, 1202.
頼朝の命により元服と同時に三浦義澄の孫娘との婚約が決められ、8年後の建仁2年（1202年）8月23日に三浦義村の娘（矢部禅尼）を正室に迎える。