Soba (そば) is a type of thin Japanese noodle made from buckwheat flour. It is served either chilled with a dipping sauce, or in hot broth as a noodle soup. Moreover, it is common in Japan to refer to any thin noodle as soba in contrast to udon which are thick noodles made from wheat. It takes three months for buckwheat to be ready for harvest, so people can harvest it four times in a year; it is harvested mainly in spring, summer, and autumn.

In Japan, buckwheat is produced mainly in Hokkaido. People call soba that is made with buckwheat that has just been harvested “shin-soba”. It has more flavor, sweetness and taste than soba.

In Japan, soba noodles are served in a variety of situations. They are a popular inexpensive fast food at train stations throughout Japan, and are served by exclusive and expensive specialty restaurants. Markets sell dried noodles and men-tsuyu, or instant noodle broth, to make home preparation easy.

Some establishments, especially cheaper and more casual ones, may serve both soba and udon (thick wheat noodles) as they are often served in a similar manner. However, soba is traditionally the noodle of choice for Tokyoites. This tradition originates from the Edo period when the population of Edo (Tokyo), being considerably wealthier than the rural poor, were more susceptible to beri beri due to their high consumption of white rice which is low in thiamine, and are thought to have made up for this by regularly eating thiamine-rich soba. Every neighbourhood had one or two soba establishments, many also serving sake, which functioned much like modern cafes where locals would drop by casually.