Tokyo Gas
, founded in 1885, is the primary provider of natural gas to the main cities of Tokyo, Kanagawa, Saitama, Chiba, Ibaraki, Tochigi, Gunma, Yamanashi, and Nagano. , Tokyo Gas is the largest natural gas utility in Japan.

Timeline
October 1, 1885, Tokyo Gas was founded by Shibusawa Eiichi and Asano Sōichirō by acquiring business of Tokyo Prefecture Gas Bureau.
1912, Tokyo Gas merged with Chiyoda Gas. 
1913, Tokyo Gas merged with Kawasaki Gas. 
1944, Tokyo Gas acquired business of Yokohama City Gas Bureau.
May 2016, Tokyo Gas merged with Chiba Gas, Tsukuba Gakuen Gas Corporation, and Miho Gas.

External links 
Tokyo Gas website (Japanese)
Tokyo Gas website (English)