[1] The general design of the trains was overseen by Noriaki Okabe Architecture Network, with the train finished in the standard Hakone Tozan Railway livery of "Vermillion Hakone" and silver highlights.

[1] The trains can operate in multiple with 3000 series EMU cars to form three-car sets.

[2][needs update] Passenger accommodation consists mostly of four-person seating bays, with a wheelchair spaces in both cars.

[2] Hakone Tozan Railway announced details of the new 3100 series train in December 2016, scheduled to enter service in May 2017.

[3] The first unit was delivered from Kawasaki Heavy Industries in Kobe in April 2017.