The Tōyoko Line is a major railway line connecting Tokyo (Shibuya) and Yokohama. The line is owned and operated by the private railway operator Tokyu Corporation. The name of the line, Tōyoko (東横), is a combination of the first characters of Tōkyō (東京) and Yokohama (横浜), and is the mainline of the Tokyu network. The section between Den-en-chofu and Hiyoshi Station is a quadruple track corridor with the Tōkyū Meguro Line.

The Seibu Ikebukuro Line is a railway line of the Japanese private railway operator Seibu Railway. It originates at Ikebukuro Station, a large railway junction in north-western Tokyo, extending to northwest suburbs as far as Tokorozawa, Saitama, and nominally terminates at Agano Station.