Ita soba is a traditional type of Japanese soba noodles, made from buckwheat. This type of soba noodles is a specialty of Yamagata Prefecture. The soba noodles are cut slightly larger than your regular soba noodles, and they're very reminiscent of soba noodles that are made in the countryside.
This is also known as the most simple soba style. The buckwheat noodles are traditionally served on large boards called ita, hence the name of the dish. Due to the fact that unpolished soba flour is used for these noodles, the aroma and texture of buckwheat is greater than in other soba types.