The younger brother of Yoshiaki MIURA, who was the family head of Miura clan that appeared at that time, named himself Yoshizane OKAZAKI and his legal son took the name of Yoshitada SANADA (written as 佐奈田 as well as 真田).
ちょうどその頃に登場した三浦氏の場合は、家長・三浦義明の弟は岡崎義実を名乗り、その嫡男は佐奈田義忠（真田とも）を名乗る。