Although some historical data (Bukejiki [the account of the military houses]) states that his real name was Masaoki, Kansei Choshu Shokafu (genealogies of vassals in Edo bakufu) only shows Okimoto as his name.
実名を昌興とする史料（武家事紀など）もあるが、寛政重修諸家譜は興元のみを載せている。