Mini-shinkansen (ミニ新幹線) is the name given to the concept of converting 1,067 mm (3 ft 6 in) narrow gauge railway lines to 1,435 mm (4 ft 8+1⁄2 in) standard gauge for use by shinkansen train services in Japan.
Work started in 1988, with Yamagata Shinkansen services commencing on 1 July 1992.
[2] The success of this initiative led to the conversion of a further 61.5 km (38.2 mi) of the line to Shinjō, opening on 4 December 1999.
Following the success of the Yamagata Shinkansen conversion, a scheme was proposed to construct a second mini-Shinkansen route from Morioka in Iwate Prefecture, then the northern terminus of the Tohoku Shinkansen, with Akita in Akita Prefecture.
[2] On 16 March 2013, E6 series trains entered service on this line, initially at a maximum speed of 300 km/h (186 mph) on the Tohoku Shinkansen section.