Morito Nishina was born in 1220. He was a descendant of Sadamori Taira and was called Jiro Nishina.
When ex-Emperor Gotoba employed the two sons of Morito for guard duty of his palace, Morito settled in Kyoto, impressed by the honor. Because of this, he was deprived of his territory in Shinano by the Kamakura Shogunate. When ex-Emperor Gotoba started a military campaign against the Shogunate (1221), Morito was ordered to defend the Hokuriku area. Morito left Kyoto for Hokurikua.