The Ube-sen today is a single-track local line which branches off the San'yô Honsen in the town of Ube, then crosses the river Kotôgawa and serves the heavily industrialised left bank of the river via Inô to the Ube port region. At Inô the Onoda-sen joins the Ube-sen from the west. The main station of the line in the port area is Ube Shinkawa. From Ube Shinkawa onwards the Ube-sen first takes on a tramway-like character as it serves the residential area to the east. After that it works up Yamaguchi Bay through a rural countryside until reaching the San'yô Honsen again at Shin Yamaguchi (formerly named Ogôri). The whole line is 33, 2 km long, and it has been electrically worked since 1929 (DC 1500 V).
Developments in the Ube to Ube port area have been very extensive and numerous branch lines for freight operation once existed here. Also, rearrangements of the track (particularly 1950-1952) led to several new sections of line here, though many plans for thorough modernisation came to nothing.
The first railway connection from Ube to the port area was built in 1914, and it was not until 1943 that the State Railways took over the line. An important customer along the line was the Ube Kôsan Chemical Industries, which was served by through freight trains (limestone trains) off the Mine-sen via Asa. Limestone, coal and other freight was also brought to Ube Port. However, the freight branch lines in the Ube port area all closed by 1961, and freight services over the Ube-sen to Ube Port itself ceased in 1999. Limestone continued to be transported by rail from the Mine-sen to Ube Port until 2009, when the Ube Kôsan Company replaced this operation by a special road for trucks.
Ube-sen trains are all relatively slow stopping services, and bus services in the region are often preferred. Until 1981 the line was noted for some of the oldest stock still in regular service in Japan.
Trains operate roughly every hour, though to a rather irregular timetable. Three trains work through from Ube Shinkawa to Asa on the San'yô Honsen, and another one to two trains all the way to Shimonoseki. In addition, Ube Shinkawa to Inô is also serviced by Onoda-sen trains.
