 Prior to the opening of the Hokkaido Shinkansen, there were also sleeping car trains between Honshu and Hokkaido, such as the "Hokutosei", "Cassiopeia", "Twilight Express", and "Hamanasu".In 1892, the Hokkaido Colliery and Railway Company opened the line from Muroran (now Higashi-Muroran) to Iwamizawa.The line was built to link coal mines in the Iwamizawa-Asahikawa region and Muroran Port.