Kochi Prefecture (historical Tosa Province), Shikoku Island, Japan
Tosa (historical name for Kochi Prefecture on Shikoku's Pacific coast) has one of Japan's most distinctive regional food cultures — shaped by its historically remote location and rich Pacific Ocean access. Key elements: Katsuo (bonito/skipjack tuna) is the defining protein — Tosa katsuo tataki with garlic (not just ginger) over straw fire is the definitive regional dish; Shimanto River produces Japan's finest freshwater ingredients (kuruma-ebi river prawn, ayu, unagi); Shikoku wheat and citrus (yuzu, konatsu); Tosazu (Tosa vinegar — dashi-enhanced rice vinegar used instead of plain rice vinegar in local preparations); Yosakoi festival drinking culture with sawachi cuisine (large shared platters of fish-centred preparations); Tosa sake (vigorous drinking culture — Tosa is famous as Japan's heaviest drinking prefecture); and Machi no Sake (town sake traditions). Kochi city's Hirome Market is one of Japan's finest concentrated food markets.
Bold, direct, confident Pacific flavours — katsuo tataki with garlic and wara smoke is assertive and satisfying; Tosazu adds dashi-deepened acidity; the cuisine is unapologetically robust compared to Kyoto's refinement
Tosa tataki differs from other katsuo tataki by using garlic slices (not just ginger) and the authentic wara (rice straw) fire smoking — the straw creates a specific light smoke character unavailable from gas or charcoal; Tosazu dressing (dashi + rice vinegar + soy + sugar + katsuobushi-steeped) is more complex than plain vinegar dressing; sawachi cuisine serves food on enormous wooden platters to large groups — the communal dining ethos is central to Tosa culture.
The Hirome Market (Kochi city) experience: arrive at noon, order Tosa tataki from Myojinmaru, sit at the communal tables, eat with cold draft beer and local shochu — this is the authentic context; Shimanto River conger eel (Shimanto unagi) is extraordinary — the clear, cold river produces leaner eel with more complex flavour than farmed; home Tosa tataki: purchase sashimi-grade katsuo block, sear over the gas burner's high flame on all four long sides, immediately ice-bath, slice thick, arrange on plate with garlic and ginger slices, doused with Tosazu.
Using ginger only for Tosa tataki (the signature is garlic + ginger together — local Kochi people are specific about this distinction from other regions' tataki); using commercial rice vinegar instead of katsuobushi-enhanced Tosazu in local preparations; ignoring the drinking culture context of Tosa food (sawachi and the elaborate Kochi drinking rituals are inseparable — the food is designed to accompany sustained sake drinking).
Japanese Food Culture — Naomichi Ishige