Osechi-ryori is a special new year's dishe to be eaten during the first three days of January. Osechi literally means food boiled and seasoned which we eat on new year's day. So, some people just say osechi. Most dishes are cooked in order to be preserved for at least three days so we do not need to prepare foods during this period. All people can then celebrate new year. 30 or 40 years ago, we cooked osechi by ourselves, but many people recently buy osechi in supermarkets, restaurants, online shopps, etc. When I went to a supermarket last weekend, I saw an advertisement to reserve osechi. I have never bought osechi in a supermarket and so on, because they are very expensive. You can see the prices in the pictures.