Initially they were associated with the Oba faction; however, when MINAMOTO no Yoritomo raised his army, they were the first to ride with him and were bestowed the characters for "Ichiban" on their family crest.
当初、大庭党に属していたが源頼朝が挙兵すると、一番に駆けつけたことから一番字という家紋を与えられた。