The fifteenth shogun Yoshinobu TOKUGAWA was of the Mito family, but he became a member of the shogun family after being adopted into the Hitotsubashi-Tokugawa family, one of Gosankyo.
なお最後の15代将軍徳川慶喜は水戸家出身だが、御三卿の一橋徳川家への養子を経て将軍家を継承した。