Keiji Osawa, former manager of the Nippon Ham Fighters professional baseball club and known by his nickname "Oyabun," or Big Daddy, died Thursday morning of gallbladder cancer, his family said. He was 78.

The native of Kanagawa Prefecture joined the Nankai Hawks, now the Softbank Hawks, in 1956 after graduating from Rikkyo University. In 1959, he led the team to the Japan Series title together with such stars as Tadashi Sugiura and Katsuya Nomura.

After retiring as a player in 1965, he joined the Tokyo Orions, now the Lotte Marines, as a coach and manager in the farm system. He became club manager in the middle of the 1971 season.

From 1976, he led the Fighters and won the Pacific League in 1981.

He became a club administrator in 1984 but reassumed the manager's position in the middle of the season.