Japanese people eat a special selection of dishes during the New Year celebration called osechi-ryōri , typically shortened to osechi. This consists of boiled seaweed , fish cakes , mashed sweet potato with chestnut , simmered burdock root , and sweetened black soybeans . Many of these dishes are sweet, sour, or dried, so they can keep without refrigeration—the culinary traditions date to a time before households had refrigerators, when most stores closed for the holidays. There are many variations of osechi, and some foods eaten in one region are not eaten in other places (or are considered unfortunate or even banned) on New Year's Day. Another popular dish is ozōni , a soup with mochi rice cake and other ingredients that differ based on various regions of Japan. Today, sashimi and sushi are often eaten, as well as non-Japanese foods. To let the overworked stomach rest, seven-herb rice soup is prepared on the seventh day of January, a day known as jinjitsu .