Nakano was the daughter of an official from Aizu, but was raised in Edo (Tokyo) where she was trained in literary and martial arts, specialising in a form of Ittō-ryū one-sword fighting. She also became a skilled instructor in the use of the naginata, a bladed polearm. She spent five years as the adopted daughter of her martials arts teacher, Akaoka Daisuke, but left him after he attempted to arrange a marriage for her. She relocated with her native family to Aizu in 1868.
During this time the Boshin War began between the ruling Tokugawa shogunate and supporters of the Imperial Court. Although the Shogun surrendered in May 1868, some of his forces continued to fight on, retreating to Aizu. Nakano joined the army in repelling the Imperial forces and fought at the Battle of Aizu, which was in effect a month-long siege.
While Aizu retainers did not allow women to fight, Nakano formed an unofficial unit of twenty women armed with naginata, including her mother and sister. The group took part in a counter-attack designed to break the siege, during which Nakano killed five enemy opponents before taking a fatal bullet to the chest. Afraid that the enemy would take her head as a trophy, she asked her sister to instead decapitate her and bury the head.
The shogunate forces eventually lost the siege to the better-armed Imperial forces. As requested, Nakano’s sister buried her head under a pine tree at the Hōkai-ji Temple and a monument was erected there in her honour. During the annual Aizu Autumn Festival, a group of young girls take part in the procession to commemorate the actions of Nakano and her band of women warriors.