Zenzai

Japanese would eat mochi (rice cake) during the period of the New Year. There is a long history and even people in 6th century ate mochi and this was for something special.
In many houses, they would eat "ozoni" or "zenzai" (it may be also called shiruko) on the New Year's day. Ozoni is salty soup with mochi and other vegetable while zenzai is sweets.

Azuki red beans will be first cooked until it becomes very soft, then add sugar, ginger juice, then finally salt to make people feel more sweetness. On the New Year's day, I made zenzai for the first time in Austria.