As somen noodles are made without any sort of preservatives, they are usually dried when they are sold. Thus most somen consumed across Japan are typically made from the dried variety.
Here are Nakabu-an, you get the rare opportunity to eat freshly-made somen that has not been dried. The result is a smooth and slightly chewy texture that you simply cannot get from raw somen. Dipped in the dipping tsuyu (つゆ) sauce, it makes for noodles that you just can't stop slurping down.
You can also try Olive Somen here, which you can only get on Shodoshima. Fusing together the two of the major local produce of olives and somen.
Nakabu-an also organizes a Somen Splitting Workshop (素麺箸分け体験, Sōmen Hashi Wake Taiken) that gives you a hands-on experience of making your own somen.