This is my second time staying at one of Kei's Airbnbs and it has been an absolute pleasure to do so. We had to book this place late (just a few weeks before our trip) because our other Airbnb fell through, but it was a blessing in disguise because it has been a very smooth and pleasant experience with Kei.
The house is as described (though with a TV rather than a projector now), and is well-located - Higashi Shinjuku station is the nearest, but Shinjuku-sanchome is also within easy walking distance. The house is also in a quiet area so you can get your rest, but there are also convenience stores nearby.
All facilities in the house were in good working condition - be it the air-conditioning, heating, hot water and washing machine. Just be aware that the dryer function takes a long time for bigger loads of laundry, so you might want to hang some clothes up instead.
The house and beds were also comfortable, and we enjoyed lounging in the tatami room :) The one limitation is that space to open up your luggage is limited, but we got around that by taking all our stuff out and leaving them in the tatami room.
Kei was responsive throughout the booking and stay, and we really appreciated their help in arranging for a large car to help take our luggage (4 large suitcases) to the Shinjuku Bus Terminal.
Overall this was an excellent stay that I'll highly recommend, and I look forward to staying with Kei again.