Hiro is an old engine from Japan.
Hiro lived and worked in Japan for many years and was then sent to Sodor. He was the first steam engine on to arrive on the island. Eventually he started to break down and was later abandoned.
Decades later, Thomas found him and got him restored. Hiro then began working on the Mainland, but he frequently made trips to Sodor and worked there as well. Sometimes he would return to Japan as well.