Konan was born as the second son of Choichi NAITO (1832-1908, his pen name was Juwan), a warrior of the Nanbu Domain, and his wife, Yoko, in Kemanai Village, Mutsu Province (present day, Kazuno City, Akita Prefecture).
陸奥国毛馬内村（けまないむら、現秋田県鹿角市）にて、南部藩武士・内藤調一（1832-1908号は十湾）と容子の次男として生まれる。