The station building was a wooden structure of traditional Japanese design with a red tiled roof and housed a ticket window and a waiting room.

On 2 December 1928, Miyaji was linked up with Tamarai, the western terminus of the Inukai Line (犬飼線), which had been extended westwards in phases from Ōita since 1914.

With the privatization of Japanese National Railways (JNR), the successor of JGR, on 1 April 1987, Akamizu station came under the control of JR Kyushu.

[4][5] Because of track damage from the 2016 Kumamoto earthquakes, service between Higo-Ōzu to Bungo-Ogi was suspended from April 2016.

[10] Media related to Akamizu Station at Wikimedia Commons This Kumamoto Prefecture railroad station-related article is a stub.