Background
Misu was born in Hikone as the eldest son in a samurai class family. His father, Misu Kumajirō, was a retainer of the Ii clan, and was assigned command of the defenses of Edo Bay against the incursions of foreign vessels. After the Meiji Restoration, in August 1872, Misu entered the fledgling Imperial Japanese Navy; however, the navy was dominated former Satsuma samurai who were highly antagonistic to people from Hikone. Furthermore, his classmate, Dewa Shigetō, was from Aizu-Wakamatsu, whose former Matsudaira lords were the sworn enemies of the Hikone Ii clan. Misu survived partly through his father's connections with Yoshida Shōin, and through the support and patronage of Ijuin Gorō.