Because he was born to a 26-year-old low-rank maid when his father, who was about to marry his lawful wife, was 19 years old, he was adopted by Masanobu SHINMI, one of the vassals of the family, and went by the name of Sakon SHINMI.
父が正室を娶る直前の19歳の時に身分の低い26歳の女中に生ませた子であったため、世間をはばかって家臣の新見正信に預けられ、養子として新見左近を名乗った。