We stayed at Masami's apartment for 10 days and we loved it. The apartment is nice size and has all the amenities including sleepers and umbrellas you can take if it rains.
It's really clean and she has the best comforters, we found hard to get out of bed some days :)
The location is very convenient, close to the Hatagaya station and it has a lot of little stores and restaurant close by.
The area is really nice and quiet, she lives next door so you can just contact her if you need any help.
Our wi-fi kept being slow and she replaced the SIM for us but that also ran out quickly, that's probably the only issue we had, so you might want to get an International Plan if you plan on using a lot of Data.
Thank you Masami!