Nobushige's father, Masayuki SANADA, asked a son of Nobushige TAKEDA, who was a younger brother of Shingen TAKEDA, to let him use the name Nobushige, and he was allowed to do so, so Nobushige did not change his name.
本名の信繁（のぶしげ）は、武田信玄の弟・武田信繁の名を是にと父真田昌幸が信繁の息子に言って使わせて貰った名であるため改名はしていない。