The E3 series (E3系) is a Japanese Shinkansen high-speed train type built for Komachi services which commenced on 3 June 1997, coinciding with the opening of the new Akita Shinkansen "mini-shinkansen" line, a regular 1,067 mm (3 ft 6 in) narrow-gauge line between Morioka and Akita re-gauged to 1,435 mm (4 ft 8+1⁄2 in) standard gauge.

Doorway steps fold out to bridge the gap between the narrow body and the platform at regular shinkansen stations.

A pre-series 5-car set, numbered S8, was delivered from Kawasaki Heavy Industries to Sendai Depot in March 1995 for extensive testing.

[4] The full-production trainsets built from 1996 for the Akita Shinkansen were 5-car sets, but sixth cars were added by the end of 1998.

[7] From the start of the 15 March 2014 timetable revision, E3 series trainsets were no longer used on Akita Shinkansen Komachi services.

[10] Three 7-car E3-1000 sets (numbered L51 – L53) were built between 1999 and 2005 for use on Yamagata Shinkansen Tsubasa services from 4 December 1999 to augment the 400 series fleet following with the extension of the line to Shinjo.

The new trains incorporate design improvements, including active suspension, full-color LED destination indicators, and AC power outlets in all cars.

[26] On 11 February 2023, set L65 was repainted into the original silver and green livery used at the time of introduction to Tsubasa services last seen in 2016.

[31] The Toreiyu set was based at Yamagata Depot and formed as shown below, with car 11 at the Fukushima end.

The children's area featured blue and white representations of toy trains by Art Unit Paramodel.

The cafe section of the car was designed by Kentaro Kobuke and served sweet items featuring local products.

The fifth car featured an abstract flower artpiece by Haruka Koujin that vibrated with the motion of the train.

[13] The Genbi Shinkansen set was based at Niigata Depot and formed as shown below, with car 11 at the Tokyo end.