Soba noodles are traditionally eaten during Japanese New Year's Eve celebrations as Toshikoshi soba.
The name Toshikoshi soba means “year-crossing soba.” People commonly eat the buckwheat noodles on December 31, often in a simple hot broth with toppings that vary by region and household. The custom is associated with crossing from the old year into the new one.
Several symbolic explanations are connected with the dish. The noodles' length can suggest longevity, while their ease of cutting is linked to leaving behind hardship from the previous year. Buckwheat is also associated in popular explanations with strength and resilience because the plant can withstand difficult weather.
The tradition is not a single standardized recipe. Ingredients and serving styles differ across Japan, and some people eat the noodles before midnight rather than exactly at the moment of transition. Mochi is another important Japanese New Year's food, but it belongs especially to broader New Year's celebrations rather than defining Toshikoshi soba.