South of Soeda the line enters the narrow mountain valley leading up to Hikosan station. Beyond, after Shakagatake Tunnel (4379 m long), trains emerge at Chikuzen Iwaya into a quiet rural landscape. Here starts the steep descent that leads down to Yoake, where the main river system flowing into Ariake Bay is reached. At Yoake the Hita Hikosan-sen joins the Kyûdai Honsen for the remaining 8,5 km to the town of Hita.
In the face of the different facets of the Hita Hikosan-sen it is not surprising that its historical development is complex. There is the line from the Jôno region to Kawara, and from there down to Soeda, which was opened in 1915 and integrated into the State Railway network in 1943. As mentioned, the direct Kawara to Soeda section closed 1985. Then there is the line from Tagawa Ita through Tagawa Gotôji and from there down to Soeda, which today forms part of the Hita Hikosan-sen; this went into traffic between 1896 and 1903, becoming part of the national network in 1907. The section from Soeda southwards to Hikosan opened in 1942, while from the south end, Yoake to Daigyôji (9,4 km up the valley) went into service between 1937 and 1946. The line was finally completed in 1956 with the opening of Shakagatake Tunnel and the section from Hikosan to Daigyôji via Chikuzen Iwaya at the southern tunnel portal. Modifications to Jôno junction and the construction of the rail link between Kawara and Tagawa Ita followed in 1957. Now it became possible to introduce through express trains from the cities in the north directly into the centre of Kyûshû.
With the demise of heavy industry and especially the coal traffic, freight services were gradually withdrawn in the 1970s. All freight traffic ceased from the Tagawa region southwards in 1986, and on the Jôno to Kawara line between 1987 and 1999. Up to 2017 there was an hourly stopping service (with some additional trains at peak hours) between Kokura and Tagawa Gotôji and mostly on to Soeda. On the southern section, we find basically 9 trains (of which 6 come through from Kokura) stopping at all stations between Soeda, Yoake and Hita.
The name of the line refers to its southern end point, the city of Hita via the Hikosan mountains.
## The Hita Hikosan-sen was devastated in the torrential rains of July 5, 2017. Serious destruction occurred to the line and the bridges between Soeda and Hikosan, while reinstatement of services on the southern side from Yoake to Chikuzen Iwaya and Shakagatake Tunnel will practically require the building of a new railway; the southern portal of Shakagatake Tunnel is flooded. Nobody can tell for the moment whether finances (including the heavy financial burden on the regional communities too) will permit reconstruction of the Hita Hikosan-sen, which is only lightly used south of Soeda. In addition, services on the Kyûdai Honsen in the Yoake and Hita area are also interrupted, following the destruction of a major bridge near Hita on the same date. ##
## In July 2020 the decision was taken not to restore the line south of Soeda but to introduce a bus service (termed BRT - Bus Rapid Transport). How far this BRT would use the old track bed was not yet clear in 2020). By the end of 2022 the rails had been lifted and the old track bed between Hikosan and Hôshuyama (including the 59 m long tunnel near Fukakura above Hikosan and through Shakagatake Tunnel - 4379 m long, altitude 844 m) asphalted and prepared for the BRT. The new bus service will be operated by JR Kyûshû and is expected to start in the summer of 2023. ##
