Seichu GENGENSAI, the eleventh head of the Urasenke school, was adopted at the age of ten from the Matsudaira family of the Okutono domain to become a husband of the daughter of Hakuso NINTOKUSAI, the tenth head of the school.
11代玄々斎精中は10代認得斎柏叟の女婿として10歳のときに奥殿藩松平家から養子に入った人である。