Keio Corporation is a private railway operator in Tokyo, Japan and the central firm of the Keio Group that is involved in transport, retail, real estate and other industries. The Keio railway network connects western suburbs of Tokyo and Sagamihara in Kanagawa with central Tokyo at Shinjuku Station. The name 'Keio' is derived from taking one character each from the places through which the railway runs: Tokyo and Hachiōji. Wikipedia