In Japan, toshikoshi soba is the New Year's Eve noodle dish associated with longevity and leaving the old year behind.
Toshikoshi soba literally means “year-crossing soba.” The custom is to eat buckwheat noodles on New Year's Eve, often in a simple hot broth. Their long, thin shape is linked symbolically with a long life, while the noodles' ease of cutting can represent breaking away from the hardships of the previous year.
The practice is widespread but flexible. Families and restaurants may serve different toppings and broths, and regional variations exist. The dish is part of Japan's end-of-year observances, alongside temple bell ringing and preparations for Shōgatsu.
It is easy to answer ramen or udon because both are familiar Japanese noodle dishes. Toshikoshi soba is more specific: the name identifies the New Year's Eve custom and the buckwheat noodle traditionally used for it.