Makunouchi Kazuo (幕之内一男) is non-recurring character in Hajime no Ippo.
Kazuo was a Fisherman on a Commercial Fishing Boat that is gone for long periods of time. It been mentions that he loved getting into fights. According to Makunouchi Hiroko, he imaged his opponent as a Fish.
Kazuo bought a new fishing boat in order to start the Makunouchi Fishing Boat business in order live live closer to his family, since Commercial Fishing Boats are gone for long period of times. Before he can start the new business, he has one last trip on the Commercial Fishing Boats before he can retire. He promises his son and wife that he will be back in a week, and that he would stay at home after that.
During the fishing trip, the ship was wrecked by a storm and rough sea. As the ship was sinking, Sakuma (a crew member) was trapped under a heavy object. Sakuma wanted Kazuo to leave him in order to save himself, but Kazuo stayed and lifted the object off of him. He throws Sakuma to the rescue boat, and stays on the sinking ship as it goes down.
After a few weeks of searching, the rescue operation for Kazuo was called off and he was declared dead. Young Ippo believe his father would returns, waits beside the dock for his return since he promised he would return. Later on, Ippo heard a voice in the middle of the night, while he was waiting at the dock for his father to come back, and he found his father's newly bought hat. Hiroko believes Kazuo return once he saw how stubborn Ippo was waiting for him to return.
He looks similar to Ippo, but more rough looking and signs of a beard growing.
- In the Flashback, it is mentioned that Hiroko was 26 years old when Kazuo died. (According the the promotion site, Hiroko was born on November 12, 1949.) So, Kazuo died in 1975, when Ippo was about 3 years old, since he was born on 11/23/1972.