“Hirame” could be translated in many ways depending of your country of origin: Flat Fish, Sole, Ｔurbot (although the latter should define “karei”) and what else. There are many varieties, wild or humanーfed. In Japanese, the names are numerous: Ｈirame, Ｓｈｉｔａｂｉｒａｍｅ， Ooguchikarei, oyanirami, etc.
The best season is Autumn to Winter. They are still available until Spring in Shizuoka Prefecture. Wild ones come from Hokkaido and Aomori. Human-fed ones mainly hail from Oita, Ehime, Mie, and Kagoshima Prefectures.
The domestic wild catch is around 7600 tonnes a year, while human-fed fish amount to around 7100 tonnes a year. A recent increase has been observed in recent years, though. A lot are imported from Korea through Fukuoka and Shimoseki.
Hirame can be enjoyed as sashimi, cut in various thickness, according to the chef’s preference and presented artfully.
I like both sashimi and nigiri, but in the case of nigiri, I have a marked preference (see pic above taken at Sushi No Ichi, Shizuoka City): Seasoned with a little lemon juice or yuzu (if available) and salt (preferably “snow salt” from Okinawa), eaten as it is with no shoyu!