We were traveling with our 5 yo daughter and this place was a great choice!
Everything was walkable and we felt super safe walking with a kid everywhere.
Kitashinagawa is such a lovely city, not too touristic/crowded yet friendly to the tourists and very lively with both old and new co-exist.
The house itself is not large but compared to any hotel rooms you can find in this area, it felt specious and comfortable for a long stay.
In such a compact space, you would find everything you would need. Well-thought amenities.
Their stuff are very friendly, attentive and helpful. We fell in love with the city, so if we ever get a chance to stay in Tokyo, we will definitely choose this place.