They were originally built for the South Manchuria Railway and the Manchukuo National Railway by ALCO of the United States in 1908, and have the distinction of being part of the first group of standard gauge locomotives to operate in northeastern China.

The first Pacifics to be delivered to Mantetsu were the seven class "G" locomotives built by ALCO at their Richmond works.

These were part of the first group of locomotives bought by Mantetsu after conversion to standard gauge.

In 1933, six were transferred to the Manchukuo National Railway, where they were used on the construction of new lines, along with regular passenger duties.

Due to the axleload of the Pashina class being too heavy for use on the mainline north of Xinjing (Changchun), after the extension of the Asia Express to Harbin in 1935, the Pashii class was used on the Xinjing–Harbin section, which was formally owned by the MNR.