Hisaie UKITA was guessed to be his son or his adopted son, who was a son of Shintoku KOJIMA (it is suspicious that he actually lived, but if he lived in reality he seems to have been a brother of his wife).
宇喜多久家は実子、或いは児島信徳（実在したか怪しい人物であるが実在したならば妻の兄か弟にあたる人物であると思われる）の息子を養子縁組したのではないかとも。