One theory holds that Tsubone's direct petition to Ieyasu was rejected, and it was only after Ieyasu visited Edo-jo Castle and saw the way Eyo (the brothers' mother) was doting upon the younger brother that he reconsidered.
この直訴はその時は失敗し、後に家康が江戸城を訪れたときにその江与の溺愛ぶりを見て考え直した、という説もある。