Tororo Soba is a Soba noodle dish with gooey grated Nagaimo.  It could be hot or cold although the recipe here is a cold version. Zaru Soba is the very basic and most popular soba dish, but Tororo Soba is also found on the menu at any Soba restaurant in Japan.  Cold Tororo Soba is a great dish during summer for Nagaimo’s rich nutrition and coolness of Soba when you don’t have much appetite from heat outside.