His origins are unclear, but there is credence to the theory based on some description in the "Nihon Ryoiki" that he was born in Nagusa no kori (or Nagusa-gun) County in Kii Province and part of the Otomo clan.
出自については不明であり、その記述から紀伊国名草郡の大伴氏の出身とする説が有力である。