It connects Gomen Station in the city of Nankoku with Nahari Station in the city of Nahari in Kōchi Prefecture.

[1] Limited-stop "Rapid" services and some all-stations "Local" services inter-run over the JR Shikoku Dosan Line to and from Kochi Station.

[1] Trains are formed of single or two-car diesel multiple units.

[1] A fleet of 11 9640 series ("9640" can be read as "Kuroshio" in Japanese) stainless steel-bodied diesel multiple unit cars are used on the line, including two cars, 9640-1S and 9640-2S with rounded front ends in a whale motif and an open observation balcony on one side.

[2] The Tosa Kuroshio Tetsudo was established on 8 May 1986 for the purpose of resuming construction of the Sukumo and Asa lines, which had been planned by Japanese National Railways but abandoned.