That is bonito flower, also called bonito flakes, which often appears in Japanese cuisine. When it is in the air, even the slightest air movement will make it move. (This paragraph is quoted from Baidu Encyclopedia Katsuobushi soup is an indispensable ingredient for cooking Japanese food, just like chicken soup in Chinese food and beef soup in Western food. Katsuobushi flower soup is made from the more precious deep-sea bonito, which has been roasted and dried for many times. Cut the bonito into thin slices and store it in a vacuum or filled with nitrogen, waiting to be used. It does not add any additives and is a natural condiment. It is rich in nutrients and can be used in Japanese cuisine, including cold salad, soup, hand rolls and various sauces. Taste the special deliciousness of bonito flowers)