5 stars. Mie was very communicative and kind, she introduced me to other guests and showed me around the local area. When winter got cold she bought me extra blankets and a heated blanket and made sure there was always oil in the heater. The flat has everything you need for cooking too.
Yanaka is a lovely area, full of temples and shrines and local businesses. There's an organic supermarket closeby and the station is about a 5 minute walk away. It's very quiet at night and you can get to any of the busy areas like Akiba, Roppongi, Ikebukuro, etc. in about 30 minutes.
I initially was going to not stay here due to lack of bath/shower being listed but that's really just a technicality. There's a shower room downstairs you can use and a free bath about 1 minute walk away that's always available. There's also public sentou in the area too. So don't worry about that.
I would definitely stay here again.