Sadakyo was diligent in his studies since he was young, studied under Shinyo EDAYOSHI and Matsudo ISHII, learned keigaku (study of Keisho in Confucianism), and was excellent in archery and the art of the spearmanship.
貞興は、少年の頃から勉学に勤しみ、枝吉神陽、石井松堂に師事し、経学を修め、槍術や馬術にも秀でていた。