is a Japanese dish made with chilled tofu and toppings.
The choice of toppings on the tofu vary among households and restaurants, but a standard combination is chopped green onion with katsuobushi (dried skipjack tuna flakes) and soy sauce. Other toppings include:
right|150px|thumb|The Hiyayakko is also known as hiyakko or yakko-dōfu. Hiya means cold, and yakko refers to the servants of samurai during the Edo period in Japan. They wore a vest on which the "nail-puller crest" was attached, on the shoulders; therefore, cutting something (e.g. tofu) into cubes was called . "Hiyakkoi" or "hyakkoi", the Tokyo dialectal term equivalent to the standard Japanese, is also a possible etymology.[1]
In the 1782 recipe book Tofu Hyakuchin, it is said that hiyayakko is so well known that it needs no introduction.
In haiku, hiyayakko is a season word for summer. This is because tofu is often enjoyed cold in the summer, warm and boiled in a broth in the winter.