[2] The "NE Train" was first delivered from Tokyu Car Corporation in April 2003, configured as the world's first hybrid diesel/battery railcar[3] and classified as KiYa E991-1.

The stainless steel bodyshell was derived from the E127-100 series EMU design, although with cabs at both ends instead of one in a married pair, two doors per side instead of three, and no gangways.

[4] Data obtained from these trials was used to develop the KiHa E200 DMU, which entered service on the Koumi Line from July 2007.

[5] The "NE Train" underwent modifications in 2006 to replace the diesel generator with a hydrogen fuel cell, becoming the world's first fuel-cell/battery hybrid railway vehicle, classified KuMoYa E995-1.

[7] The railcar was test-run within Ōmiya Works from October 2009, with test running on the Utsunomiya Line under consideration from January 2010.