In addition, according to the section on Munetaka SAMEJIMA in the 'Honpan-Jinbutsushi' (Personages of Satsuma), there was a concubine of Yoshihisa's called Kojijyu who bore a male child after she was granted to Sukemitsu KIWAKI, giving rise to the theory that there was a child born out of wedlock, but she does not appear in official historical records, and the credibility of the account, including the existense of a concubine, is low.
そのほか、「本藩人物志」鮫島宗堯の項に、義久の側室とされる小侍従なる女性が木脇祐光に下げ渡された後に男児を生んだ（鮫島宗堯）としていることから、落胤説もあるが公式史料には登場せず、小侍従の存在を含めて信憑性は低い。