The privately run Hokkaido Railway opened the station on 18 July 1904 when it extended its track between Ranshima and Shikaribetsu southwards to it. The track was extended further south from Kozawa to Neppu by 19 Oct 1904, establishing through traffic all the way to Hakodate. After the Hokkaido Railway was nationalized on 1 July 1907, Japanese Government Railways (JGR) took over control of the station. On 12 October 1909 the station became part of the Hakodate Main Line. On 1 April 1987, with the privatization of Japanese National Railways (JNR), the successor of JGR, the station came under the control of JR Hokkaido. From 1 October 2007, station numbering was introduced on JR Hokkaido lines, with Kozawa Station becoming "S22".
^ abIshino, Tetsu et al. (eds.) (1998). 停車場変遷大事典 国鉄・JR編 [Station Transition Directory - JNR/JR] (in Japanese). II. Tokyo: JTB Corporation. p. 812. ISBN4533029809.CS1 maint: Extra text: authors list (link)
^Ishino, Tetsu et al. (eds.) (1998). 停車場変遷大事典 国鉄・JR編 [Station Transition Directory - JNR/JR] (in Japanese). I. Tokyo: JTB Corporation. p. 240. ISBN4533029809.CS1 maint: Extra text: authors list (link)
^駅番号表示(駅ナンバリング)を実施します [Station number to be introduced] (pdf). News release (in Japanese). Hokkaido Railway Company. 12 September 2007. Retrieved 30 July 2015.