[4] Externally, the locomotives are finished in a bright red livery to aid visibility, with yellow and black diagonal warning stripes at the ends.

[1][5] The first full-production locomotive, HD300-1, delivered in January 2012, while broadly identical to the prototype HD300-901 locomotive, incorporates a few minor improvements, including changes to the headlamps, a wider front-end warning panel to reduce snow build-up on the steps, and larger windows in the driving cab doors to improve visibility.

[5] The locomotive was moved to Sapporo Freight Terminal in Hokkaido in January 2011 to assess battery performance and adhesion in cold winter conditions.

[6] The prototype locomotive entered revenue service from 11 July 2011, on shunting operations at Tokyo Freight Terminal.

[9] In November 2014, the first Class HD300-500 locomotive, HD300-501, designed for operations in cold-climate areas, was delivered to Naebo Depot in Hokkaido.