The name "San'in Honsen" actually refers to 673, 8 km of railway line that is not traversed by any train in its full length. "San'in" 山陰means "the shady side," or the "cold side" of the mountain range that makes up western Japan's main island Honshû. San'in is the region along the Japan Sea coast, and it is often symbolised by the setting sun; photographs of the setting sun over the Japan Sea or Lake Shinji in the Matsue - Izumo region are often used to draw attention to this part of Japan. By contrast, the other side of the central mountain range of western Japan is called the San'yô 山陽, that is "the sunny side," or the "warm side" of the mountain range, extending from the Bay of Ôsaka all along the Inland Sea down to Shimonoseki.
The San'in Honsen can be divided into several segments, with trains operating either within one segment, or linking two segments.
Segment 2: Kinosaki Onsen - Izumo. The San'in Honsen from Kinosaki Onsen westward is single-track diesel operated (merely some short sections in the Yonago and Izumo region are double track). At the eastern end of this section most trains run to and from Toyooka, where they are serviced (Toyooka to Kinosaki Onsen is 9,6 km in length ). After leaving Kinosaki Onsen there is a short section through the mountains, before the line reaches the Japan Sea. Here characteristic small villages nestle in the bays and inlets of this wild part of Japan. Trains pass through numerous tunnels to Kasumi (22 km from Kinosaki Onsen), where some of the services end. After Kasumi we soon come to what was doubtlessly the most important landmark of the entire San'in Honsen, namely the red Amarube steel trestle bridge, built in 1912. The bridge was replaced by a new structure in 2010, but some vertical supporters and girders have been retained, and an observation area has been created next to Amarube halt on the western embankment.
Continuing over the pass and the summit tunnel (Tôkan Tunnel, 1992 m long), trains reach Hamasaka (39, 9 km from Kinosaki Onsen), where passengers usually need to change for the onward journey. Shortly after, the border from Hyôgo into Tottori prefecture is crossed, and soon the train descends into Tottori city, 72,3 km from Kinosaki Onsen.
At Tottori the San'in Honsen meets the direct line across the mountains from Kyôto and Ôsaka; the centre part of this line is owned by the private Chizu Kyûkô Railway Company, while the last 31,9 km down to Tottori form part of JR's Imbi-sen. A number of Chizu Kyûkô diesel express services from Kyôto continue along the San'in Honsen westward to Kurayoshi, 39, 8 km from Tottori.
Local services between Kinosaki Onsen and Tottori are offered roughly once an hour, though only few trains run right through. There is also an express service here with class 188/189 diesel sets coming from Ôsaka via Himeji and the Bantan-sen; these terminate at Hamasaka (one to two services), at Kasumi (one service), and at Tottori (one service).
At Tottori class 187 diesel express sets begin their long journey westward along the San'in coast, three to Yonago, one to Hamada, three to Masuda, and two all the way from Tottori via Masuda and over the pass to Shin Yamaguchi, where passengers can change to the Sanyô Shinkansen (a third such service is provided from Yonago, while in the opposite direction one express runs through to Tottori).
From Tottori westward there are stopping or semi-fast services to Yonago or Izumo; the distance to Yonago is 93 km, and to Izumo 154, 3 km.
Shortly before Yonago, the electrified Hakubi-sen feeds into the San'in Honsen, coming from Okayama, Kurashiki and Niimi. The junction between the two lines at Hôki Daisen has a marshalling yard, which is also reached by container trains from Okayama. Except at Hôki Daisen no more freight can be seen along the San'in Honsen. Freight services ended in 1987, apart from a short section between Hôki Daisen and the Matsue area, which ceased in 2015.
Services between between Hôki Daisen and the towns of Yonago, Matsue and Izumo are frequent; they consist partly of diesel trains from Tottori, and partly of electric local and express trains coming off the Hakubi-sen. Also, there is an electric sleeping car set from Tôkyô, which runs via the Hakubi-sen to Izumo. Electric services end at Izumo town, but trains continue 4, 8 km to reach their servicing point at Nishi Izumo.
From Yonago westward the line follows the shore of the Nakanoumi, the lake linked by a narrow passage to the Japan Sea up at Sakai. Between Matsue and Shinji, San'in Honsen trains provide a good view over Lake Shinji (Shinjiko), Japan's seventh largest lake.
There is a well-used rail connection from Yonago up the peninsula to the port of Sakai (Sakai-sen, 17, 9 km). Moreover, just after Izumo station there used to be a branch line (Taisha-sen, 7, 5 km long) serving the Grand Izumo Shrine to the north west. This line served local transport needs as well as pilgrim traffic by large groups of pilgrims coming from all over the country to visit the Izumo Shrine. As pilgrims now come by bus, and there is another rail connection by means of the Ichibata Electric Railway (Ichibata Dentetsu), the Taisha-sen ("Line to the Grand Shrine") closed in 1990.
A further line now closed was the Kurayoshi-sen, which used to run from Kurayoshi into the mountain valley as far as Yamamori (20 km) and closed in 1985.
In contrast to railway lines on the San'yô side of Western Japan, the San'in Honsen has always had the character of a very local line passing through mostly small, coastal settlements. Not surprisingly, this line still operated steam locomotives until November 30, 1974, and continued to use ancient passenger stock hauled by diesel locomotives for many years after.
The earliest railway lines in the area were those from the port of Sakai through Yonago to Kurayoshi (1902/3), and from Yonago to Matsue and Izumo (1908-1910). The full length of the San'in Honsen from Kyôto through Kinosaki Onsen and Tottori as far as Izumo was completed by 1912.
