The Toden Arakawa Line , branded as the Tokyo Sakura Tram , is a hybrid light rail/tram line in Tokyo, Japan, operated by the Tokyo Metropolitan Bureau of Transportation (Toei). The Arakawa Line is the sole survivor of Tokyo's once-extensive Tokyo Toden streetcar system. It is one of the only two tram lines in Tokyo, besides the Tokyu Setagaya Line.

The 4 ft 6 in track gauge, also called the Scotch gauge, was adopted by early 19th century railways mainly in the Lanarkshire area of Scotland. It differed from the gauge of 4 ft 8 in that was used on some early lines in England. Early railways chose their own gauge, but later in the century interchange of equipment was facilitated by establishing a uniform rail gauge across railways: the 'standard gauge' of 4 ft 8+1⁄2 in. In the early 1840s standard gauge lines began to be constructed in Scotland, and all the Scotch gauge lines were eventually converted to standard gauge. The building of new Scotch gauge railways was outlawed in Great Britain in 1846 by the Regulating the Gauge of Railways Act 1846. From 1903, tram lines of Tokyo adopted this gauge.