Since 1883, when the nation's first electric power company, Tokyo Electric Lighting Co., was founded, Japan's electric power industry has developed largely through private enterprise. The exception was the period 1939-1951, spanning World War II and the Allied Occupation, when it was under state control. This path of development contrasts sharply with that of another electricity-related enterprise, the telecommunications industry. The Ministry of Communications also controlled telecommunications during and just after the war, but unlike the electric industry, telecommunications had no history as a private enterprise at any time from its start in 1869 until it was privatized in 1985. Until that year, the government ran it either directly or indirectly. This article reviews the history and development of Japan's electric power industry and analyzes the influential role of Matsunaga Yasuzaemon (1875-1971) in that process. While identifying the factors that lay behind Matsunaga's enormous contributions to the industry, it explains the reasons that the electric power industry, in contrast with telecommunications, has been run predominantly as a private enterprise.