Soba (そば or 蕎麦?) 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 (thick wheat noodles). It takes three months for buckwheat to be ready for harvest, so it can be harvested four times a year, mainly in spring, summer, and autumn. In Japan, buckwheat is produced mainly in Hokkaido.1
Soba that is made with newly-harvested buckwheat is called "shin-soba". It is sweeter and more flavorful than regular soba.