While he was performing in Osaka, Jakuemon NAKAMURA Ⅰrecognized his natural talent so Sojuro was adopted by his wife's family (Daigoro MIMASU Ⅳ was his wife's father) and in July 1860, he was given the name Gennosuke MIMASU Ⅲto succeed the name of his dead brother-in-law.
大坂で活躍するうち、その素質を中村雀右衛門(初代)に認められ、幹部俳優の三枡大五郎(4代目)の婿養子となり、万延元年八月(1860年7月)、死亡した義兄の名をおそって三代目三枡源之助を襲名。