Shou to Daichi(1982)

Hagiwara Shou, a young boy, lived happily with his father, a strong sailor, and his dog-fighter, Daichi, who aspires to become a Yokozuna. However, while trying to save his friends, his father was swept away by a storm and disappeared into the northern seas. Now without any family to call his own, Shou goes to live with Hatayama, who runs a boxing gym. There, he begins training hard in boxing with friends in similar circumstances...!?

(Source: Shueisha, translated)