[2] The seats on this set were originally brown, but this was later changed to the standard light green colour.

[1] It was withdrawn from service in July 2021, and was transported from Shinrin-koen to Kitatatebayashi on 16 and 17 October 2023, where it is expected to be scrapped.

An additional set, 9108, was built in 1991, based on the 10030 series lightweight body style.

[5] These incorporated further design improvements and changes similar to the 20050 series trains, notably VVVF control, bolsterless bogies, 3-colour LED destination indicators, LCD interior passenger information displays, and brown seat moquette.

Externally, single-arm pantographs were fitted, and the destination indicator blinds replaced with full-colour LED displays.