It is said that the origin of the family was from Yoshitoki's descendants, which had once relied on the Oyama clan in Shimotsuke Province and later settled in Mikawa following Rennyo (head-priest of the Jodo Shinshu sect [the True Pure Land Sect of Buddhism]).
これは、義時の子孫のうち、一時下野国の小山氏を頼っていた一族が、蓮如に随行して三河に流れ着き、定住したのがはじまりという。