Using a new online tool I discovered called "google" I managed to find the following in only 3.86 seconds...
TOKYO ACCOMMODATION GUIDE - Ryokan, Hostel, Hotel in Tokyo
Try using
Google next time, but please don't tell anyone I told you
Actually I know that the Nezu/Sendagi area has a few of these places and that you can use the Hibya line to get there. I guess that helps.
You should note that some temples (jinjya) also take guests and can offer a much better experience if you are willing to abstain from sex and meat