The Ryokan Sansuiso is an urban ryokan in Tokyo located in Gotanda (two stations from Shinkawa and 3 from Shibuya), ie, well located and with a very affordable price with respect to its location.
It's run by a very friendly pair of Japanese grandparents (along with other employees)/
The distribution is typical Japanese ryokan with tatami rooms (you sleep on a futon) and the bathrooms just like the Japanese baths are shared by all guests in a common area. This could be inconvenient if some visitors aren't accustomed to the Japanese living style and recently they've added a bathroom and shower in one of the double rooms, but just one, that's usually the first to be reserved.
I've been to this ryokan many times and I'm very satisfied with the service.