When Naosuke was still a heyazumi (an adult-age eldest son who has yet to come into his inheritance), he devoted himself to many hobbies, including Sado, Nohgaku (the art of Noh theater), Confucianism, Japanese classical literature, the Soto sect of Zen Buddhism, calligraphy, painting, poetry, as well as Japanese martial arts: swordplay, spearmanship, Japanese archery, gunnery, and jujutsu.
部屋住みの時代に儒学、国学、曹洞宗の禅、書、絵、歌、剣術・抜刀術・槍術・弓術・砲術・柔術などの日本武術、茶道、能楽などの多数の趣味に没頭していた。