It is said that the Naito family was a descendent of Masatoyo NAITO, a busho (Japanese military commander) in the Sengoku period (period of warring states) and Konan, at his father's order, visited Masatoyo's grave in the remains of Nagashino battlefiled.
戦国武将内藤昌豊の子孫であるという家系伝承を持ち、湖南は父・十湾の命で長篠古戦場跡の昌豊の墓を訪ねたことがあるという。