Highway Bus or JR?
If you travel between four main cities in Shikoku; Takamatsu City 高松市, Matsuyama City 松山市, Tokushima City 徳島市, and Kochi City 高知市, highway bus is cheaper than JR Express Train.
The bus takes more time but not so much to care or even faster between Matsuyama and Kochi.
If you are a student in Japan, show your Student ID at the ticket counter for a discount.
UPDATED Aug 7, 2021