Definitely five star! Thanks very much Hiro for all the quick and kind helps!
Pros:
Spacious house, close to parks, nice Japanese-style bath room equipped with jacuzzi bath, fast internet, baby/toddler toys
Cons:
This house occupies the 1st and 2nd floors of the building. 3rd or upper floor residences were a bit noisy during my stay. In addition, this house is (almost) inaccessible with car which could be because of an ongoing construction as of 2020 Dec. However, I still give a five star since everything else was EXCELLENT for this price.
Thanks again Hiro! We will stay here again when we come to Tokyo in the future.