[3] The station, which is unstaffed, consists of a side platform serving a single track at grade.

The station building, a modern concrete structure, is unstaffed and serves only as a waiting room.

[2][3] The private Miyazaki Light Railway (宮崎軽便鉄道) (later renamed the Miyazaki Railway) opened the station on 22 October 1923 with the name Aoshima Onsen (青島温泉) as an additional station on a line which it had laid in 1913 between Minami-Miyazaki and Uchiumi (now closed).

Subsequently, Japanese National Railways (JNR) extended its then Shibushi Line north from Kitagō towards Minami-Miyazaki on the same route and reopened Kodomonokuni as an intermediate station on 8 May 1963.

With the privatization of JNR on 1 April 1987, the station came under the control of JR Kyushu.