Hiya-yakko : It's a cold tofu dish with many toppings. Yakko means tofu in Japanese. It's a popular appetizer often served during the summer in Japan. Cold tofu is called hiyayakko and is the most popular Japanese tofu dish. All you need to do is place toppings on top of chilled tofu. It's a great appetizer for summer. Cut tofu into halves. Serve tofu in individual bowls. Put grated ginger, dried bonito flakes, and chopped green onion on top of tofu as much as you like. Pour some soy sauce before eating. Put some karashi mustard if you would like.