Aki Ishihara
Google
The best traditional sweet shop in Japan! Kurumi-mochi is Sakai's specialty in all times since the 14th century. It's delicious, not too sweet but good sweet. And the shop itself has a very nice traditional design. You should definitely order the one with shaved ice, and eat the ice together with mochi under it. Please be careful not to finish the ice too quick. It's better to balance it with mochi. The shop is usually very crowded in summer even on weekdays, but all customers leave soon after they finish eating, so the lines move very fast. Sometimes the sweet gets sold out around 3pm, so you'd better go before then.