Sea bream is marinated in kombu, gizzard shad in vinegar; sushi rice is seasoned with red vinegar and salt. The scrupulous training the chef received as an apprentice pervades every aspect of the restaurant. Nigirizushi begins with pale white-flesh fish. Tuna, served three pieces in succession, leaves an impact. Sushi rice is served on the warm side, the better to bring out the sweetness of the fish oil. Simmered conger eel brings the meal to a close, as in the old days. The restaurant stands on the river’s edge, so you can watch the boats plying the waters below as you dine.