[2] As he was born when the country was still under rule by the Tokugawa Bakufu, he was sent on 12 October 1852 into the Buddhist priesthood, and assigned to serve at the monzeki temple of Chion-in in Kyoto.

On 27 October 1860, he was recalled by Emperor Kōmei, who formally adopted him as a potential heir to the throne.

The Meiji Restoration in 1868 eliminated the possibility that he would become Shōgun, and Prince Hirotsune returned to the Imperial household.

Emperor Meiji granted him permission to start a new branch of the Imperial Family, and he took the name of Kachō-no-miya (from the mountain name of the temple of Chion-in).

He studied at the United States Naval Academy at Annapolis in 1870, but fell ill and returned to Japan in 1872.