Ohga was born in Numazu, Shizuoka. When he was a child, he suffered tuberculosis that kept him in bed for a long time during which an acquaintance taught him physics and music. As a young man, Ohga aspired to be a professional opera singer, and went on to read at the prestigious Tokyo National University of Fine Arts and Music, graduating in 1953.
Ohga was made the president of Sony in 1982, and the CEO of Sony in 1989. That same year, Ohga purchased Columbia Pictures Entertainment (currently Sony Pictures Entertainment) from the Coca-Cola Company for $3.4 billion.A year earlier, Ohga acquired the CBS Records Group (currently Sony Music Entertainment) from Columbia Broadcasting System. Ohga also played a key role in establishing Sony Computer Entertainment in 1993. Ohga supported Ken Kutaragi to develop the PlayStation as a Sony-owned console.
In 1994 Ohga succeeded co-founder Akio Morita as Sony chairman. The next year Ohga selected Nobuyuki Idei as the company’s next president, a decision Ohga later told author John Nathan appalled 99 out of 100 people at the company, and it led to a sweeping reorganization of the company. Indeed, Idei lasted until 2005 when he was succeeded by Howard Stringer. Idei became Co-CEO with Ohga in 1998, and sole CEO in 1999.
In 2000 Ohga became semi-retired, staying Chairman of the Board while Idei became Executive Chairman, and on Ohga’s 73rd birthday in 2003 Ohga retired from the board and became Honorary Chairman. In later years, Ohga developed a driving ambition to conduct great orchestras. Ohga died in Tokyo.