The location of Chie's house is excellent. Not only is it a 5-minute walk from Shin-Okubo Station, but there were many convenience shops and supermarkets nearby which was extremely convenient for all of us.
Though the house was abit small for 15 of us, we were impressed with the cleanliness and tidiness of the house. There were also no shortages of amenities in the house that helped to make our stay very comfortable. However when considering the space required to place items such as suitcases, I think that staying in as a group of 10, rather than 15, would provide the most comfortable experience for everyone.
I would definitely recommend Chie's place for any large groups looking to stay at a convenient location in Tokyo.