 The direct descendant of the famed Uesugi Kenshin, Mochinori was born in 1844.Mochinori's father Narinori took part in the movements of the northern domains which culminated in the creation of the Ōuetsu Reppan Dōmei during the Boshin War.After the end of the war, Narinori was made to retire, and Mochinori became lord of Yonezawa in his place.