The owner, Kouzi is very friendly and hospitable. He made mini map/manuals to show us his recommendations to eat out as well as public bath house and supermarket. Also it is recommended to fly in to Haneda instead of Narita if you are planning to visit Tokyo, because it is way closer.
The apartment is 5 mins away from subway and convenience store (super important). G&R House will be my first option when I decide to go to Tokyo again.
Rice cooker, stove, toaster oven, microwave, refrigerator, plates, soup bowls, eating utensils are extremely useful during our stay there.
Please be aware that Japan has strict recycling laws that everybody has to abide to, Kouzi has provided plenty of instructions in the room on how to recycle.
TL:DR I've enjoyed my stay very much