This is an interesting place and my only Recommended one for this weekend. Along a quite street leading north west from JR Musashi-Shinjo station (Nambu Line) there is Menya Shinnosuke. It's a clean and well-lit shop, a bit like a diner, on the corner of the street. Interesting murals, paintings, and trinkets from Hawaii line the walls and shelves. I didn't ask but I get the sense that the owner lived or visited Hawaii. For whatever reason this place is not on Tabelog or Livedoor. They have a very extensive menu, they are more like a Chinese restaurant than a ramen shop. In any case they have a specially-made (tokusei) dan-dan men that you can choose your own broth style for: tomato, shio, tonkotsu, shoyu. Then they put a generous amount of noodles and also some egg (sort of egg-drop-soup style) in and bring it over. The staff was really friendly and helpful and they have a really wide range of other noodle and side dishes too. The soup was excellent and a huge portion. Clearly this place is a bit out of the way for many people so it is hard for me to suggest that this is worth a special trip but if you are in the area I definitely recommend it.
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Diddlefinger Map (English labels)