O-sechi ryouri/御節料理 is traditional new year’s food in Japan.
The word literally means “節”/sechi seasonal or festivity “料理”/ryouri dishes.
There was a lot of cooking to be done, so in advance people would cook tiered layered boxes with foods that keep well.
The boxes you serve and store osechi in are like bento boxes, called jubako/重箱.
There are many traditional small dishes within the osechi ryouri.
The dishes also have special meanings.
For example, the giant shrimp symbolise the hope for a long life.
That’s because the shrimp looks a little like an old man – long antennae are the beard and the bent waist is the hunched back of the elderly.
Use your imagination a little bit!
For some more detail, you can check out rocket news.
Happy New Year!