Osechi

Osechi-ryōri (御節料理, お節料理 or おせち) are traditional Japanese New Year foods. The tradition started in the Heian period (794–1185). "Osechi" are easily recognizable by their special boxes called "jūbako" (重箱), which resemble "bentō" boxes. Like "bentō" boxes, "jūbako" are often kept stacked before and after use.
Examples of osechi dishes.
The dishes that make up "osechi" each have a special meaning celebrating the New Year. Some examples are:
History.
The term "osechi" originally referred to "o-sechi", a season or significant period. New Year's Day was one of the five seasonal festivals in the Imperial Court in Kyoto. This custom of celebrating particular days was introduced from China into Japan.
Originally, during the first three days of the New Year, it was taboo to use a hearth and cook meals, except when cooking "zōni". Osechi was made by the close of the previous year, as women did not cook in the New Year.
In the earliest days, "osechi" consisted only of "nimono", boiled vegetables with soy sauce and sugar or mirin. Over the generations, the variety of food included in "osechi" has increased. Today it may refer to anything prepared specially for the New Year, and some foreign dishes have been adopted as "Westernized "osechi"" (西洋お節 "seiyō-osechi") or as "Korean-style "osechi"" (朝鮮のお節 "chōsen no osechi"). And while "osechi" was traditionally prepared at home, it is also sold ready-made in specialty stores, grocery stores, and even convenience stores, such as 7-Eleven.
Especially in households where "osechi" is still homemade, "toshi-koshi soba" (年越し蕎麦) is eaten on New Year's Eve. Its name literally means "year-crossing soba." Although there may be some symbolism attributed to it (i.e., long life, health and energy in the upcoming year), this tradition may be regarded as largely pragmatic: the traditional wife, busy cooking several days' worth of food for everyone, would likely prefer to make something simple for immediate consumption. It is considered bad luck by many Japanese to leave any "toshi-koshi soba" uneaten.