in 1909, the yamanote line began service between shinagawa and akabane, and it was called the "shinagawa line" at that time. a train consisted of 10 cars. the circular line began in 1925. a train schedule 5 trains/hour 72 minutes/a round in 1925, 25 trains/hour 60 minutes/a round in 2014 [1]. in 1961, the train color changed from brown to yellow. in 1972, the train color changed from yellow to green. in 1987, japan railway was privatized. in 1990, the yamanote line added one more car to the trains. wrapping advertisement, using yamanote line, has started since 2000. each station are installing the platform screen doors for the tokyo olympics in 2020.