We had a great time here with our 5 year old and 1 year old. It is a fantastic traditional (but updated) Japanese house. They even left an umbrella stroller and some baby toys for us to use during our stay. I was glad that we brought a peapod tent for the baby to sleep in, as the stairs are very steep and there's no good way to create a baby gate upstairs. (We could have slept downstairs, but would have had the same issue keeping the baby out of the kitchen and genkan). The hosts were very accommodating to let us have a BBQ party on the back patio (we arranged with them ahead of time). The weather was extremely hot the entire 10 days of our stay, but the air conditioning worked great and kept us comfortable when we were inside. There is a washing machine, but we opted to go to the coin laundry not far (towards Higashi Ikebukuro) to wash/dry 4 people's stuff quickly. It was easy to do. There are a few grocery stores close by, which made shopping and cooking easy. The pocket wifi had trouble holding its charge, but we found free wifi most places we were in the city.
I lived in Japan for 8 years, and this house made me feel as if my daughter was getting a true sense of living in Japan. It made me happy to stay here, and I hope to stay here again in the future.