Shimōsa (train)

The Shimōsa (しもうさ) is a rapid service train operated by East Japan Railway Company (JR East) in the Tokyo Metropolitan Area of Japan. It operates primarily on the Musashino Line, connecting destinations in Saitama, Chiba, and Tokyo. Specifically, the Shimōsa service typically runs between Ōmiya in Saitama Prefecture and Nishi-Funabashi in Chiba Prefecture, utilizing the Musashino Line and portions of the Tōhoku Main Line (for access to Ōmiya) and the Keiyō Line (for access to Nishi-Funabashi).

The Shimōsa service was introduced to provide a more convenient and faster connection between the residential areas along the Musashino Line and major transportation hubs, offering an alternative to local services. The train primarily serves commuters traveling to and from work or school.

The name Shimōsa is derived from Shimōsa Province, a former province of Japan that encompassed parts of modern-day Chiba Prefecture and Ibaraki Prefecture.