Mimasaka-Osaki

Weekday departures: 18/day · Sat & holiday departures: 18/day

First / last departure (weekday): 6:30 / 21:15

Busiest hour: 7:00–8:00 (2)

0:00 ─ 23:00

Figures are typical departures in the timetable data, not a live service count.

Timetable data as of 2 May 2026.

• Kishin Line: Higashi-Tsuyama ⇄ Nishi-Katsumada

Mimasaka-Ōsaki Station opened on 28 November 1934, when the Railway Ministry's Himezu West Line (now the Kishin Line) opened between Mimasaka-Emi and Higashi-Tsuyama. At the time it was located in Fukuriki, Ōsaki village, Katsuta District, Okayama Prefecture. When the Himeji–Higashi-Tsuyama section was completed through on 8 April 1936, the Himezu West Line became part of the Himezu Line and this station came under it; on 10 October of the same year the Himezu Line was incorporated into the Kishin Line. Freight handling ended on 1 March 1962, and parcel handling ended along with unstaffing on 12 March 1973. It became a JR West station at the division and privatization of JNR on 1 April 1987. It is a ground-level station with a single side platform on the left facing Tsuyama, with no station building — passengers enter the platform directly. It is an unstaffed station managed by Tsuyama Station, and no automatic ticket vending machine is installed.

The former Ōsaki village of Katsuta District, from which the station's name derives, is properly read with a voiced sound as "Ōzaki," differing in voicing from the station name's reading, "Ōsaki."