The Toei Shinjuku Line is a rapid transit line in Tokyo and Chiba Prefecture, Japan, operated by Tokyo Metropolitan Bureau of Transportation (Toei). The line runs between Motoyawata Station in Ichikawa, Chiba in the east and Shinjuku Station in the west. At Shinjuku, most trains continue as through services to Sasazuka Station on the Keiō New Line, with some services continuing to Hashimoto Station in Sagamihara, Kanagawa via the Keiō Line and the Keiō Sagamihara Line.

Motoyawata Station is a junction passenger railway station in the city of Ichikawa, Chiba, Japan, operated by East Japan Railway Company and Tokyo Metropolitan Bureau of Transportation. It is the only station on the Toei Subway that is located in Chiba Prefecture.