Kōchi has some of the best food in Shikoku, centred on the extraordinary local bonito. Katsuo no tataki — bonito seared briefly over a straw fire then served sliced with garlic, ginger, and ponzu — is the dish you must eat here. The city's izakayas are lively and inexpensive, and the local yuzu (citrus) flavours everything from dressings to sake.
Hirome Ichiba (listed under Things to Do) is the easiest and most atmospheric place to eat, but the smaller izakayas around the covered Obiyamachi arcade are worth exploring in the evening.