Before coming to Sodor, Hiro worked on an unnamed railway line in Japan, which ran through snowy mountains and villages. It was also on this railway that Hiro received the title, "Master of the Railway". Eventually, Hiro was shipped off to the North Western Railway to become the railway's first engine, but he returned to his home railway after he was rediscovered and overhauled. The railway is run by the line's controller, Sir Takaboushi Hideki. Hiro's friends also work on this railway.

Since the fourteenth series, Hiro no longer seems to work on his home railway, and has been usually seen working on the North Western Railway of the Island of Sodor. Since the seventeenth series, he now appears to work on the Other Railway.

The railway only appeared in Hero of the Rails via flashback scenes. Hiro later mentioned it a few times in later seasons.