Oshokuji Dokoro Shiosai
A diner near Miyanoura Port on Yakushima Island. Ask any taxi driver or local and they will say 'Shiosai for lunch' - this is the island's most trusted restaurant. Opened by a veteran hotel head chef, the restaurant is known for freshly-caught local fish dishes. Ranked #1 on TripAdvisor for Yakushima Town (4.3/5, 130+ reviews). Despite being in guidebooks, this is genuinely a local everyday eatery.
Many reviews say 'ask any local and they name Shiosai' and 'recommended by my taxi driver.' The kubiori-saba mackerel sashimi is praised as 'the freshest fish I have ever tasted.' The shrimp fry amazes guests with 'unbelievable quality at this price.' Some note it caters to tourists, but locals are regulars too.