Tucked away on a back corner in Akihabara, west of Chuo Dori and just north of the User Side PC Shop,is Toushomen Sou. Toshomen refers to noodles that are cut by hand slice by slice (sometimes very fast) from a large block of dough right into the pot, by a guy in the back, in between drags on a cigarette. The dough does not have as long to dry (after it is made but before it goes into the pot) as it does with other noodles, so the noodles tend to be a bit mushier after cooking, but very fresh tasting as you can imagine. The L-shaped counter in the store is up two or three steps, open-air, large doors and windows give the shop an open-air feeling. The ticket machine is outside under the awning. I recommend the shiru nashi men (汁なし麺), noodles and "sauce" or oil. but no soup. You don't get anything else with it. Be sure to bring a drink or sit near the water pitcher since this dish is pretty hot. It will be served very quickly and it is very spicy, lots of ground pork and hot sauce on top of a set of noodles and moyashis, almost like a thick sauce with noodles in it. It would be nice if the noodles were a bit firmer, the whole thing gets a little bit squirmy in the bowl. However it was a decently-sized portion and had some nice parsley-type greens on top. Good after a day of browsing the west side of Akihabara near Ogawamachi.
Livedoor Gourmet page (more pictures)
Diddlefinger Map (English labels)