I had this on my list of places to visit on my last stay in Japan (March 2013), but happened to be passing it when on my way to the Keiyo line to go to Maihama and Disney Sea, so popped in for lunch. It was really busy, full of Japanese businessmen and young people on their lunch break whilst in the JR station. It is unusual to see a veg* restaurant abroad be so packed with local people, who probably aren't veg* themselves.
Service was lightening quick - I was shown to a large table and given the menu. I ordered the original ramen, which looked like the least spicy option! It was bought out in minutes and was delicious! The broth was very flavourful, and with a kick but not too much. It was topped with what looked like a mix of peanut butter and soy - tasted much yummier than it sounds! It was really hot temperature wise and slurping was necessary to cool it down. It was only Y750 and completely filling, healthy and fast.
The second time I went I also had the fried soy meat, which I didn't care for much, but the ramen is incredible.
The restaurant also sells a selection of packaged foods in the entrance, including dried soy mince.
The staff don't speak much English, but the menu is in English and there are only a few options to choose from, so you can't go wrong really. At the end, you take your order sheet to the counter to pay - simple!
If you aren't in the station to get a train, you can get a station only ticket on any of the JR ticket machines; I think it is only Y300 or so. I had a JR pass, so no problem going in to Keiyo Street.Pros: So cheap!, Delicious ramen, Very fast service