Tokyo Electric Power Co. used to be the only electricity supplier in Tokyo and the rest of the Kanto region, as well as parts of Yamanashi and Shizuoka prefectures.
But that's no longer the case, thanks to the partial liberalization of the electricity market that began in March 2000, paving the way for companies and other major power users to find other sources of electricity.
A third of the large buildings in the heart of Tokyo get their electricity from companies other than Tepco, according to Shigeru Kimura, Tepco's executive officer in charge of sales and business.