[1] The name was formerly used for a limited express sleeping car service operated by JNR from 1961, which ran from Tokyo to Kumamoto, and was discontinued in December 1994.

[citation needed] Foreigners traveling with a Japan Rail Pass are required to purchase a special ticket to use the Mizuho service.

[7] From 1 June 1963, 20 series coaches were added to the formation, and the train divided and joined at Moji to serve Oita via the Nippo Main Line in addition to Kumamoto.

By 15 March 2014, there were six daily return workings per direction, with two trains stopping at Himeji to boost connectivity in the Kansai region.

As of 14 March 2020, there are eight daily return workings per direction, with some trains making additional stops at Sendai, Kurume, Shin-Yamaguchi, Fukuyama or Himeji.