We enjoyed our stay at Kaoru's place. The house itself as was spacious and clean, with excellent kitchens and bathrooms. The upper bedrooms are bright and had good storage options although the lower room is a bit dark and lacks any cupboards.
My one criticism is that the furniture was definitely pretty worn and old, and not up to the standard of the rest of the house. It really let the place down.
The location is interesting, close to a pretty vibrant area but in a quiet residential street. It is not far from the JR Yamanote line station, which is very useful. (The nearest subway is 15-20 minutes away which does mean some walking or train changing if you want to travel beyond the Yamanote line, but it was never a problem for us.)
There are plenty of nearby convenience stores although a full supermarket is a bit further away. There are many good places to eat, including at branch of Genki Sushi opposite the station, which is always a good option.
Overall it was a good base.