Most famous for his submarine mangas, Ozawa, a former assistant of Tezuka Osamu, started out drawing shoujo manga. His debut title was 1957's "Rumi shinanaide", published in Koubunsha's Shoujo, written under the pen name Ozawa Akira.

Ozawa had his breakthrough in 1963 by Submarine 707, which became an instant smash hit and established him as one of the most popular artists of the decade.

By the early 70's his popularity somewhat dwindled. His biggest success of this time was not a manga, but the designs for a plastic toy robot called Robodacchi. During this time he also occasionally used the pen name Kitazawa Riki.

Interest in his works picked up again in the 90's and peaked when his 1966 hit Ao no 6-gou was adapted into a high-profile OVA by Studio Gonzo.