This cosy, family-style shop is credited as the inventor, in 1966, of the retasu maki (lettuce roll) sushi, in which crunchy lettuce substitutes for nori (seaweed) around shrimp, rice and house-made mayonnaise. A mere ¥1000 gets you a plate of the rolls or an assortment including more typical, super-fresh, sushi. This being Kyūshū, there's a great shōchū selection.
Look for the whitewashed facade with gold characters and sushi models in cases.