In 1915, the Daito Railway Co. opened the 22 km Oita - Onoya section.

The company was nationalised in 1922, and westerly extensions were undertaken in stages from 1923 until Amagase was reached in 1933.

[citation needed] CTC signalling was commissioned over the entire line in 1984, and freight services ceased in 1987.

On 5 July 2017, torrential rainfall washed out the bridge over the Oita River between Chikugo Oisha and Teruoka, resulting in the closure of the section.

According to the Japanese language Wikipedia article, the line was fully re-opened on 14 July 2018.